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Energous and FCC Approval for Mid Range Device - What Does It Mean?

Six months ago wireless power company Energous claimed they'd have FCC approval for their at-distance charging, and I was highly skepti...

Monday, January 15, 2018

IoWTF?

I'm happy, because there's finally a chance for me to write about something other than Energous - in this case to return to the topic of "Things That Just Shouldn't Be". Previous recipients of this attention have been Juicero (the "Keurig for Juice") and June (a $1500 toaster oven). Today it's the turn of Sunflower by ShadeCraft - The World's First Robotic Shading System which you can now pre-order for delivery this fall.


Not content with just being a shade, this has everything you've always thought you needed when out on the deck in the sun. It's got lights in case the shade is a little too much, WiFi in case your phone lacks that kind of connectivity, speakers (Harmon-Kardon!), an app to control it in case your lazy ass can't stand up and move it,  security cameras to stop someone stealing your shade because they're jelly, solar power to keep it all going, and of course Artificial Intelligence in case you're too dumb to work out how to operate it. I'm surprised it doesn't mine bitcoins for you. Among any list of "first world problems", this product has to be pretty near the top of it.


I had missed the initial publicity for this product when apparently it was 'launched' at CES almost exactly one year ago. According to Crunchbase, the company was founded in March 2016, and received seed funding of $2 million in March 2017. So 9 months after founding, the company exhibited at CES to launch a product (concept only?), then raised its funding 3 months after that, and now a year after initial launch you can pre-order and get it in almost a year. 

If you have to have one of these beauties, I suggest you order it soon - you can get it today for the massively discounted price of $5,220. (Yes, Five thousand two hundred and twenty dollars) Don't wait, because at the end of the month it goes up to $6,900, followed by $7,800 in March, and $8,700 in April. Yes, nearly $9,000 for a garden shade with speakers, a camera, and WiFi. Oh, and an app.

What on earth is going on here? Even at $1000 each for speakers, camera, shade itself, motors, and solar panels you can't hit that number. Any good engineering project includes as one of the constraints a cost target, based on who the target market is. In this case, either that wasn't done, or the target market is people who have so much money they can just throw it away. Like trying to sell a juicer for $700, this is going to have a hard time - or maybe it's $8000 of pure profit and they're counting on only selling a few.

A clue as to what they may be thinking comes from looking at a previous product from the famed CEO/Founder, Armen Sevada Gharabegian. You've heard of him, of course - the designer of... The Maximillian Chair.


Want one of these gorgeous chairs? That'll be $25,000 please! And no wonder, as apparently it took him seven years to design. Don't worry though, you get a certificate of authenticity with it. So I'm going to go back to what I said earlier and say "This shade is for people with too much money."

Armen must be a talented guy as according to Crunchbase he's the only employee at Shadecraft. If he's not designing and building it himself, then that would mean that CES was used to raise interest in a then non-existent product on pretty sketches and mock-ups, to raise $2 million of seed, to pay outside design houses to get to a prototype, to put on pre-sale to get the money to build to deliver (or to show interest to raise another round). If so, it's a pretty nice way of bypassing a Kickstarter - though the designers should maybe have been given a little bit more of a cost constraint.

This will be interesting to see if the production, logistics, and other support costs have been properly factored into the pre-sale price, and the expected pre-sale volume predicted correctly. Get that wrong and you might end up with not enough orders to get manufacturing discounts you were counting on, or cover the unexpected costs and delays of hardware development. Kickstarter and other pre-sold hardware companies, such as Lily, have a long history of such 'ambitious' projects failing to deliver. Good luck to them.

It looks like they have grand ambitions and the sky is the limit for size - here's one of the images from a recent patent application. (Yes, a patent application for an internet connected umbrella).


If that's to scale, that's a pretty big shade. I wonder what that will cost?

Saturday, January 13, 2018

Tech Journalism Fail: Energous at CES

One of the reasons I write about Energous so much is that it's an ideal vehicle to show how tech journalism is manipulated by startups to give what are essentially Press Releases disguised as reporting. When you read most tech coverage you rarely see journalists speak to experts in the field, or press for deeper answers on questions, taking for granted statements from the company in question even when they have been shown to repeatedly be 'less than truthful'. 

In part it's understandable as some of these topics are just difficult to understand due to the technical complexity, giving leeway for the company to use 'smoke and mirrors' to bamboozle. PR companies ensure that exclusives and early previews only go to the reliably compliant (I'm looking at you, David Pogue), cutting out from future access anyone who asks difficult questions. Journalists are also under tight deadlines and the system encourages more, lower quality articles that get attention rather than a smaller number of less feel-good but very detailed and accurate pieces - essentially, journalists are responding to the incentives the system offers. That's one reason I try to support, with actual dollars, publications that allow long term detailed investigations such as John Carreyrou's expose of Theranos.

During this last week was CES, the Consumer Electronics Show, and Energous were using this to give private demos of their latest tech to a select few. My recent post on Energous tried to lay out some questions to help journalists at least try to probe past the marketing fluff, but from what I've seen of the CES coverage, it's clear I need to work on my blog exposure! Barron's had at least some questions over long term viability and Tiernan Ray is one of the very few to actually get an outside opinion, using a phrase I constantly bring up with wireless power - possible but not practical. The weakest that I've seen so far has been from Tom's Guide which I'm pretty sad about as in its early days Tom's Hardware was a go-to site for in-depth tech analysis. What I do like about it though is that there is a video of the tech on display, and gives us more insight into what's going on.

First of all, I suggest you go to the Tom's Guide site and watch the video through. (See, I told you the 'access based journalism' gets more hits!).

Basic Research Anyone?
First thing is that the journalist immediately sets the expectations by saying that the at-distance charging will "start showing up in products you will buy in about 12 to 18 months". Barring the fact that if you want to show up in mass-market products you have to have deals signed 12 to 18 months prior to the product actually appearing, apparently it was too hard to go an look back and see examples of Energous using a "time-to-carrot" of product 18 months out since at least early 2014. Why believe them this time, or at least mention that the company has a history of being wrong about their timing?

As an aside, why do journalists need to use adjectives when describing the technology such as 'cool'? If it's actually 'cool' then the reporting will show that without the need to lead readers so bluntly - but I do understand that the company PR people will love them for it.

The Demo
We then move to a demo charging devices - you can see the transmitting antenna underneath a monitor, with the keyboard and mouse sitting about 1 foot away. There's a statement that WattUp Mid-Field goes up to 250 mW, but apparently it's not worth saying "Hey Energous rep, show me something charging with this at 250 mW". Instead we see the keyboard receiving around 67 mW at close range, dropping to around 20 mW at 2 feet or so. This is a far cry from even the >100 mW at 50 cm that the CEO was claiming last week, or the "12 devices, 15 feet, 4 watts" from 2 years ago.

The keyboard is much bigger and should support ideally sized antenna, so why that low? Why the inconsistency? But you'd have to know the technical details and have done your homework to ask that. (I expect part of that is due to the antenna being horizontal - move the keyboard vertical and the number may have gone up. That would have been nice to see - if only someone had maybe suggested you do that...)

Perhaps someone might even have thought to ask:

"Hey, your FCC Approval says that it switches off and won't charge below 30 mW. Why am I seeing 20 mW here? Is this different than the FCC approved system?"

Next you have a 'cool' part of the tech where the transmitter can prioritize between the devices being charged, like a keyboard and a mouse. It's "sophisticated enough to support scheduling capability".  Isn't that cool and smart? No, no it isn't. The obvious question to ask here is:

"So you can barely charge at mW level, and can't even charge more than one device at a time?"

Everyone does realize that the marketing team just got a major technology limit spun positively as a feature, right?

Safety Last
Next comes safety. In the article Energous get to plant a direct PR quote without any questioning:

An Energous rep said that the company’s sub-gigahertz technology transmits at well below the SAR (specific absorption rate) for phones, and that its beam-forming technology is precise enough to direct energy only in the direction of the gadgets being powered.

Did anyone perhaps think to ask:

"Great - What value is SAR limited to and what are you transmitting at?"

or

"Awesome - can you show me some beam plots proving your highest power is exactly on the receiver?"

or perhaps even

"You say you target small "pockets" of energy - how big are they across?"

because it's not as if anyone has laid it out that they are basically at the SAR limit, the beamforming is so poor they can rarely get the highest power at the target, or that the 'pockets' are 50 centimeters across. And that's from the company's own data in the FCC report. Yes, I know that I'm a nobody blogger, but there are so many people that could have been called up, like a university electrical engineering prof, and just asked what should be looked for. Without asking anyone else who might know, this is just being a mouthpiece for Energous PR. I'm sure they are grateful for it.

That's not the worst part of the safety question though. It's an integral part of the Energous FCC approval, which even they themselves admit is required, that there is a safety system that shuts off when there is movement within 50 centimeters of the transmitter. The video makes it very clear that there is no such safety system here, so how about asking:

Your FCC approved system shuts off for 30 seconds when anyone is within 50 centimeters. I'm clearly in that range. Why is this still working? Am I exceeding consumer SAR limits right now?

This is not the system approved under FCC Part 18 (one hard-to-spot give-away to this is that the transmitter is a completely different shape) and I expected them to try this which is why I wrote out the question to ask which was:

"Are we, right now, operating under the same safety limits and other restrictions a consumer system would have to?"

It's not that hard to ask, and the answer would quite likely be "no" (or some mumbling) and then it would be a more interesting story! (Hint, the sign right in front of you literally says "This device has not been authorized as required by the rules of the Federal Communications Commission")

Anyway, it's not my health, so congratulations to the journalist for being brave enough to potentially put himself outside those limits for the sake of Energous' share price - sorry, I mean informing his readers.

More Power
That's enough about safety, after all who cares about that? Now we come to 'high power devices' like phones which you can charge at 7.5 Watts (7500 mW!). The same technology that can only charge a keyboard at 67 mW is suddenly charging 100 times higher. Cool! Except what is missed, and the Energous rep was very happy not to correct, is that the sign next to that demo says quite clearly "WattUp Near-Field High Power Demo" not the "WattUp Mid-Field Demo" just walked away from. This is completely different and now incompatible technology (0.9 GHz vs 5.8 GHz) and now gives readers the impression that the at-distance charging will work with phones at 7.5 Watts. 

Just because they use the same name, WattUp, doesn't make them compatible. If it were capable of that wouldn't they be charging the keyboard like that? This isn't a little difference, it's a factor of 100!

This is a basic failure to understand the products being reported on and quite literally misinforming readers to the benefit of Energous. 

See the power of branding and names like WattUp to cover multiple differing technologies? Awesome for confusing the rubes customers.

The phone, which is connected to the contact charging device by a USB cable, is then moved closer to the charging brick and apparently the charge rate increased. What? If distance was a factor, why have the cable? 

Here's the next thing missed. As the phone is moved we hear "it's up to 875 mW", while knocking the charging brick it's connected to off at an angle and away from the charging pads underneath the monitor base. Then there's a sudden cut in the video (at 1m 25s) where it's obvious the Energous rep stepped in and squared the brick up, and now it's charging at 3.57 W. So hey how about someone asking:

"Is this near-field technology so sensitive that knocking things slightly changes charge rates by a factor of 4?"

Perhaps it's worth asking because that's in direct contradiction to the Energous PR statement printed which was:

Energous says its solution allows for greater “rotational freedom” over coil based technologies.

Even when the video evidence contradicts them, some journalists still say what the company hands to them, unquestioned. It's a little clearer in the text, but the ambiguity the mistake introduces will be used by the company to their benefit.

Last techy questions to have asked here since this Near-Field demo also had the sign saying it wasn't FCC approved:

"Could any currently FCC approved devices charge at this rate?"

and

"And isn't this charging brick limited to 300 mW charging as-per the recent FCC Approval?"

But, again, that would have required homework, and an understanding of the difference between the two charging technologies that Energous call "WattUp".

But Their Products...
There are still some stubbornly skeptical people so at the end, it's clearly pointed out that WattUp is now in a product, so obviously it's real. Who wouldn't want underwear that needs charged? The tech is so awesome and cool that everyone is knocking on Energous' door, but of course who wants Apple to use you in their product, the real market is tighty-whities!

Saying that it's a WattUp receiver lets readers think that it will charge at a distance, when the FitBit-style tracker component actually needs removed and charged in contact with the near-field device. It's also only available as a pre-order which means it's not actually available as a product yet

Once again putting two different and currently incompatible technologies under the same brand name, WattUp, allows Energous to play reporters and get incorrect but favourable reporting.

Lastly, there's a mention of "Tier 1" device makers and that it will take time for Energous to get them into their devices. But haven't Energous been teasing their relationship with a "Tier 1" for years, letting everyone think it's Apple until it became clear last year that it wasn't? Who is it now then? I ask because they people who keep mentioning "Tier 1" are Energous themselves, as it gives them a sense of mystery and importance, and everyone obligingly just repeats what's said to them. It wouldn't be that those "Tier 1" comments came from an Energous rep or handout, would it?

It's a tough job to do right
It's perhaps unfair to pick on this one reporter, there are many weak regurgitations of Energous PR out there such as Digital Trends talking about the "awesome new wireless charging tech" but the video shown here just highlights how much more sophisticated company marketing is than most of the press reporting on them. They know exactly how to use marketing terms and change up demonstrations to misdirect and confuse, allowing beneficial errors to pass, and correct those not in their favour. Complex technology in particular gives great leeway for obfuscation and if there isn't someone with a tech background helping, then it's going to be more of a Press Release Laundering Service rather than actual reporting. But hey, it gets a lot of page views, right?

To summarize
At CES Energous showed off a Mid-Field Transmitter that did not meet FCC rules, and clearly differs from the Mid-Field Transmitter approved under Part 18. They also showed off Near-Field charging technology that hid multiple charging pads under a monitor, needs a large charging-brick that won't fit into a phone case and was not FCC approved, as well as a smaller Near-Field charging technology that charges much slower. All four different versions are called "WattUp" and work as designed - which is to confuse and make everyone think they're all the same thing, that way it's easier for journalists to give positive coverage rather than report on the complexity. Nicely done Energous marketing team!

Final note: As every time I post something on Energous I get accused of being in a short position and writing for financial gain in trying to drive the stock price down, I'll once again note that I have no financial stake here, either long or short. So many people find it hard to understand why I write these posts if not for money, and unfortunately there's nothing I can do to persuade them that other motivations do exist.

Friday, January 12, 2018

Quick Summary: Energous's Week at CES

Even I'm getting tired of writing about Energous, but it's just been a very hectic last couple of weeks with their FCC approval and demoing their tech (to a select few) at CES. While most of the original commentary I can give relates to the technology and the rather woeful press coverage of it, there were a few other events to track.

Products?
Energous announced a pre-order of the first products to use 'WattUp' charging, and it did help boost the stock price for a little while. What was this amazing product? Underwear. With fitness trackers. For $400 in a 4-pack. Yes, really. The stock buying public was clearly wowed about the at-distance wireless charging, though in the end it turned out that the fitness tracker needs removed from the underwear and placed on the Near Field charging device (comes with the 4-pack) that is incompatible with the at-distance charging. And it's a pre-order, not actual availability, so it's a little disappointing really...

Earnings?
Energous then released the 8K for their 2017 4th quarter, basically their financial report. It was a bit weak with only $30,000 of revenue from "engineering services" (consulting) - which to put in perspective is what most engineers with moderate experience can charge for their individual services, not what you'd expect from a company with a market cap of $500 million. Their burn rate is around $11.5 million per quarter, and they had around $12.8 million in the bank at the end of 2017. Not a healthy financial picture, especially when you read that they admit that their revenues in 2018 will be 'modest' despite claims both Near-Field and Mid-Range products will be available in 2018. Seems weird, don't they expect anyone to buy their products?

This was a pretty poor performance, and the stock price reacted accordingly. It makes it all the more concerning that the insiders sold their stock only a few days prior to the 8K. The executives must have known this was coming, and the SEC usually frowns on sales under these conditions.

Raising money?
In order to keep going, Energous is selling shares in the company, up to $40 million worth. This sale will dilute existing share holders - like the ones who bought on hearing the FCC announcement a couple of weeks ago. With what the company has in the bank, and their current burn rate, that will do them until February 2019 - though given they say that they don't expect significant revenues before then, I'm not sure what they do at that point.

CTO?
On Thursday it was also announced that Michael Leabman, Founder and CTO, would be leaving his role effective immediately. This was a bizarre announcement, as it's very unusual for this to happen at such a time. Why leave after a great success like the FCC approval, and during the best 'publicity week' of the year? Unlike the usual Energous PR, there wasn't the media friendly PR packet waiting with the "having achieved his goal of at-distance wireless charging, Michael now wants to spend more time with his family" style blurb. It was several hours before that appeared, and the sudden departure, rather than a transition to his contractor role, was odd. We don't have enough information to know and draw an accurate conclusion, but it was very strange.

CEO?
The CEO gave an interview with Barron's, which also raised some eyebrows. Unfortunately for most of you, it's behind a paywall, but I'll summarize (and I'll encourage you to pay, Tiernan Ray seems to have done the best of the mainstream press covering Energous).
  • We exaggerated in the past and got things wrong, but trust us moving forward
  • What was I supposed to do, the press want to hear something
  • Still claiming smartphone charging at 15 to 18 feet in 2019, though says "one to two watts or 100s of milliwatts" - nicely hedged there.
  • Apple suck because they can't deliver Qi charging mats
  • Qi sucks because it knocks out Bluetooth
  • Still being mysterious about their "tier one" partner and playing that game

Most of it was what I'd expect, but taking a shot at Apple is pretty surprising. I guess they won't be working with them anytime soon!

Stock?
Despite the glorious week of CES, the stock price took a tumble, from a high of around $26 to a low of around $20. This is a volatile stock and will bounce around for a while, but that's quite a fall from the $33 only two weeks ago. Let's see where it goes this week, and if there's going to be a hangover for some people.

That's it, have a great week everyone.

Final Note: I actually posted this on the night of Sunday 14th, but dated it the 12th to keep it underneath the Tech journalism post, in case you notice. And now the apparently obligatory notice - I have no stock position on Energous, I'm not being paid to write this.

Monday, January 8, 2018

Tech Journalists: Questions for Energous at CES

Tech journalists can come under a lot of fire for failing to ask the difficult technical questions many in the field want answered, and sometimes let companies away with pretty egregious statements. Now, reporting aggressively can lose you access, but for the many journalists who want to do a good job and ask the right questions, how to do basic preparation when a topic can require years of study to truly get to grips with?

To help out those journalists going to CES and will be seeing Energous' new system in operation, I thought I'd give some handy helpful questions so there's no getting the most from your interview time. (Of course, I'd tell you to read all my blog posts on Energous too, but let's make it easy...)

Speak to a technical expert - don't take the company word at face value
First point - talk to other engineers or physicists like me who can help you - ask these questions of Energous. Seriously, you can get in touch with me here, I can put you in touch with others, and there are academics and industry experts who will help out. Don't take the initial answers the company gives, they'll try and dodge if you ask good questions. Notice where they get uncomfortable and press there. Get specifics, don't allow them to handwave. If you ask for a number and don't get it, but do get a wordy story, they're avoiding giving it to you. They have FCC data now, no excuses. Ask again and again until you get that number.

What is this thing?
Second - know what they're showing. They used to claim it will charge phones, they're a long way from that. Their FCC Part 18 approved device needs a safety cutoff because of international limits, to charge a device at around 100 to 200 mW at best, wastes at least 99% of the energy, has a tiny limited zone it can be used in, is a fraction of the performance of what was promised over the last few years, and those safety limits will likely prevent them increasing power or distance.

So here we go:

What's your use-case for this system? Who buys it? How long will it take to charge my phone? Can people use their devices while they charge? Do I have to stand in a limited area. Will moving affect charging? What's going to be the first product and when?
Alarm bells if they can't give you a clear answer or waffle on about chargeable clothing or the like. 

Are we, right now, operating under the same safety limits and other restrictions a consumer system would have to?
If not, why not? What's the difference? Am I safe? (Familiarize yourself with SAR - International safety limits)

Why do you need a keep-out-zone? Why is it at 50 centimeters? 

What size is that device that's being charged? IPhone X? Or Fitbit?
The dimensions matter. Ask how power would change with a much bigger or smaller device. Get numbers. If it's a wearable, ask about phones.

What much power is that device you are showing receiving?
Now you might get get the answer "it's really variable and depends on circumstances" to which the next question is:
OK, so how much power with this receiver under ideal circumstances of position and orientation?
Ask what those conditions are. Position. Distance. Orientation. In numbers. (See the very bottom for some comparison numbers)

Can you prove that, with a power meter? Don't let lighting LEDs wow you. Demand proof.

Is that within or outside the "keep-out" zone? Company statements last week indicated that there would be less than 200 mWatts received at the edge of the "keep-out-zone" of 50 cm. Are we exceeding international SAR limits right now? 

How long to charge this device at that rate?  How long would an iPhone take?

What happens if it rotates at an angle, or I move it further away? Maximum distance, and how power dips as the receiver rotates.

Is that RF energy received, or actually converted to power at the battery? Odds are it's a 60 to 70% conversion efficiency from one to the other, they'll want to give you the bigger of the two.

What's the efficiency? Is that calculated from the wall socket, or the transmit antenna? Efficiency is calculated with a power in, and a power out - make sure you know where those two powers are measured. You want wall socket to battery.

Your MS300a receiver: Why is it so much thicker than a phone? Does it have any batteries or charge storing capability? The FCC documents say 300 mW received, is that RF received or converted at the battery? At what distance does it receive that much? (Added 1/9/18)

Those are the initial questions to ask - finding out power versus distance, orientation of receiver, efficiency, and whether you're in the "keep out zone". Don't be put off by "oh that number depends on the circumstances" - press them with specific circumstances. Ask for "best case scenario" for a consumer, then ask what distance, orientation, are for those powers and efficiencies. Then ask about different circumstances of distance and orientation. Watch the wording carefully - slight differences in terminology matter.

Now the most important question:

Why isn't the system putting out more power? "FCC Part 18" is supposed to be unlimited power. Only charging at ~100 mW? Why not more? What's stopping you? Are you operating at the international SAR limit? If not, how far away from it are you? How will you get more powerful systems if this is a limit? If they are at these safety limits, it's indicative the power can never increased further in any future products. 

Update 14th Jan: It looks like Energous are trying to pre-empt SAR questions by stating their system "transmits at well below the SAR for phones" but not stating what the limit is or what they are transmitting at. Journalists, ask for numbers for both! Their response here indicates they are sensitive to this question.

How much power is the transmitter sending out? Is that conducted power? ERP? EIRP? Ask them to be very specific, those terms matter. (I expect for this device it's 10 Watts transmitted, 30W ERP, 50W EIRP - see how different they are?) Once you get conducted power, ask for the wall socket power. They do know it.

How large are your "pockets" of power? Dimensions please. Your FCC SAR Report shows them as at least 50 centimeters across (half power). Why so big?

How well does the power track the receiver? Are the highest regions of power always on the receiver? The FCC SAR report shows that maximum power isn't always at the receiver. Why not? 

In January 2015 here at CES you gave demos and said "up to 12 devices, up to 15 feet, up to 4 Watts". So what are those numbers for this system? How long until you get to those 2015 numbers? How close will you get? What's stopping you getting there?

In January 2016 here at CES you showed antenna receiving power at 1.6 Watts. Why can't you do that now? What's the difference?

Earlier this year you said this would work with the WattUp Mini. That's 5.8GHz and contact charging, this is 0.913 GHz. Will they operate together? Why not? Will they ever? What changed? Did the FCC deny you certification at 5.8 and 2.4 GHz?

The FCC Approval says your safety system won't detect inanimate objects. What happens if someone falls unconscious in the keep out zone and just their head is in there. Will the system start working again after 30 seconds and expose the person to dangerous energy? What happens if the sensors get blocked? Under what other circumstances might it fail?

What technology does the safety detection system use? IR/Radar? What frequency? Is it close to 913 MHz? Shouldn't it use the same energy as the power transmission? Why did you design a safety system for motion, not presence of people or pets?

Why did the executives and so many big shareholders sell large amounts of their stock last week?  Aren't they confident of where the company will be moving forward?

How did you get the FCC Chairman to tweet about Energous? Isn't that against government rules to single out companies like that?

Finally, a question for me. Do you use the same type of antenna on send as receive? What type are they? Half-wave dipole, patch, or something else?

That'll do to begin with - I'll add more as I think of them. And to repeat - talk to someone who understands the technology, this is a tricky subject, and Energous are very polished in giving vague answers!

Power numbers
1 Watt (W) is 1000 milliWatts (mW) which itself is 1000 microWatts (uW). So 1 Watt is 1 million microWatts
An iPhone needs between 500 and 1000 milliWatts (mW) to start charging. So that's 0.5 to 1 Watts.
Qi charging/AirPower in the latest iPhone is 7.5 Watts. It will likely fully charge the phone in 2 to 3 hours.100 mW is 75 times slower than this, 30 mW is 250 times slower than this.
Apple AirPods have a 1.5 Wh battery, so around 15 hours to a day to charge at 100mW. If you stand still in a tiny charge zone.




Update 1/8/18: Looks like they're hiding their technology from most, so only tame journalists are likely to get to see it. Still, now they've no excuses for not asking the right questions in their article. Hear that David PogueFrom their press release:

Energous will be taking private meetings and demos at the Venetian, alongside Dialog, on an appointment-only basis, at CES 2018, the world's largest consumer electronics show, January 9-12 in Las Vegas, NV

Thursday, January 4, 2018

Another Energous Insider Sale - This time for up to $43 million

So it looks like Malcom Fairbairn of Ascend Capital just sold a chunk of Energous stock. He had put in $20 million in August 2016 for which he appears to have obtained 15.5% of the company.

SEC's EDGAR site data (summarized here) shows he sold 809,061 shares on the 27th December, and 1,162,300 on 4th January, down to 4.5% of stock - leaving just 29% of what the company had held only a couple of weeks ago.

Depending upon when he sold on the 4th, he may have received around $22 per share, while the stock sold on the 27th could have been anywhere from $17 to $22 per share. That gives $25,570,600 from the sale on the 4th, and between around $13.5 and $17.8 million on the 27th for somewhere between $39 and $43.4 million, leaving around $23 million of stock (at the 4th January's prices).

A number of directors, including Martin Cooper, received a stock grant at a cost of $0 - 26,929 shares and at 4th January prices that is as much as $600,000 each. Cooper (@MartyMobile) was mentioned in the FCC Chairman's questionable tweet about Energous Part 18 approval.

The most important thing to notice though is that Ascend Capital, one of the largest investor in Energous for the last 18 months, just sold >70% of their holding, just before, what we the company would like us to believe is a huge ramp up in the company's fortunes. For a company well placed to "take over the world", the insiders sure are keen to sell.

Update 13th Jan 2018: A poster on SeekingAlpha reminded me that once below 5% holdings there's no requirement for a stockholder to report a sale to the SEC. That 4.5% that remained of Ascend's original 15.5% could be gone. If it has been sold, at a price of $22, that's a further $22.8 million dollars.

Monday, January 1, 2018

Further Safety Limits for Energous? MPE

It's just as well Energous got their FCC Part 18 approval in a holiday period - any other week and I simply wouldn't have had the time to read the reports, analyze them, and write these blog posts. (You can find these earlier posts here) Over the last four days it's been around 7,500 words and 15 pages worth of writing, and there was a lot of reading and work for each of those pages. This will likely be the last in-depth analysis for a few days, as I actually have to get back to real work tomorrow - the exception possibly being a short piece on Powercast I'm working on and may finish tonight (Edit: nope, that didn't happen).

Here's the main point of this post - Maximum Permissible Exposure is a further safety limitation for RF radiation that has not been applied to the approved Energous system, as far as I can see. If it were, using limiting power density for the general public, my calculations say they're over the limit by a factor of 3. If they use the "Controlled Exposure" higher limits, then they are within the limit (just) - however in that case this is a system that would not be allowed to be used around the general public. I can't find exemptions that would apply so I'm wondering why it's not implemented for Energous, or if they are simply not admitting this is a system not fit for consumers.

Update: Energous may be classifying their transmitter as "mobile" to allow them to select the more lenient SAR tests than the MPE. 

Maximum Power Exposure - MPE
Re-reading FCC regulations (fun times!) I found another safety limitation for RF that I had forgotten about. While the FCC Part 18 approval documents cover the Specific Absorption Rate (SAR), where Energous sit right at the limit of at 50 centimeters (hence the keep-out/danger zone), there is also Maximum Permissible Exposure or MPE. The FCC document detailing this can be found here, it's Title 47, Section 1, 1310. Table 1 lists the exposure limits for the general public.


The power density limit is set as f/1500, where f is the frequency in MHz. Given the frequency for Energous is 913 MHz that sets the maximum power per cm2 at 0.61mW/cm2. An iPhoneX has a surface area of 14.4 by 7.1 = 102 cm2, so if the MPE limit is to be observed then maximum power to an iPhone X at any distance, in a perfect orientation, is 62 mW. Assuming a 60% conversion efficiency from RF to DC that means no more than about 37 mW at the battery.

Energous are claiming 100 mW received or more at the 50 cm mark, so I'm now confused as to how this is possible without exceeding the MPE. There are apparently exemptions for mobile transmitters, listed here under 2.1093, but they define this as:

For purposes of this section, a portable device is defined as a transmitting device designed to be used so that the radiating structure(s) of the device is/are within 20 centimeters of the body of the user. 

Given there is a "keep-out" zone at 50 centimeters and it is supposed to be "at-a-distance" wireless charging, it's really hard to imagine how they can get this exemption. Even then the only benefit seems to be that the system can use duty cycle to calculate the power - so if Energous were to, at the 100 mW received range, run their system for 3.7 seconds on then 6.3 seconds off, constantly repeating (or equivalent) then they could meet the 62 mW RF power density limit. 

So if MPE were to be applied Energous would, in addition to their (IMO) half-assed and useless safety zone, need to switch the system off about 2/3 of the time in any 30 minute period of charging. If they manage to up the power from where they are now, not only will the keep-out zone increase in size, they'd have to decrease the duty-cycle further as well.

Not Usable by the Public?
The only other way I can see this regulation not applying is if they use the less stringent safety limits for Occupational/Controlled Exposure. These are 5 times higher than for the general public (f/300 rather than f/1500). This would place the maximum RF power received by an iPhone X under ideal circumstances at 310 mW, which at 60% efficiency translates to 186 mW at the battery - barely more than the 100 mW currently received (apparently), and essentially within a 2 to 3 dB safety margin usually required. Once again, by my calculations, the Energous system as-is sits at the safety limit and cannot increase power from here. Worse, if the general public exposure limits are applied then the system power, these numbers say it would have to be reduced by a factor of 3 from the already low values.


Wearables and MPE
Things get much worse now for consumer wearables as well - for a 2 by 2 cm patch (big for a wearable), that 4 cm2 will get you a stunning 2.44 mW of RF power, or 1.5 mW after conversion. That would be enough to charge your AirPods in about 4 days. Patch antenna would also be highly directional.

Does MPE Apply to Energous?
So how do Energous get away without meeting the Maximum Power Exposure limit? I don't see it referenced anywhere in the FCC Part 18 approval documents. It's not as if they don't know about it, an IEEE Spectrum interview with CTO Leabman in January 2016 has him admitting the MPE applies:

IEEE Spectrum: When you go through this process with the FCC, is it like they have this checklist of criteria you have to fulfill in order to be safe, or is it much more nuanced than that?

Leabman: Yes and no. Certainly there are regulations for RF, what's safe and what's not safe. There's SAR [specific absorption rate] for your phone. There's MPE [maximum permissible exposure]. The nice thing about RF is that they know what's safe, and they have regulations, so in that respect, that's known. 

I've tried to find other exemptions to MPE in the regulations, but so far have not. If there are any readers with a knowledge of FCC RF regulations and MPE who care to let me know, I'd appreciate that. I'll update this post should I find that.

Edit: In discussion with some other engineers, the KDB 447498 D01 General RF Exposure Guidance document may offer some insight here. Energous may be classifying their device as "mobile" under 47 CFR 2.1091 by meeting the requirement that it is not "physically secured at one location", is "able to be easily moved to another location", and that the user is at least 20 cm from the transmitter. In this case, they may be using this section to choose between SAR or MPE as the limit. Given MPE is the more stringent of the two, I can see why they chose SAR instead. Further, this document shows why they picked 50 cm as the "keep-out zone" as there appears to be a different way SAR is calculated when you cross that 50 cm boundary, and the safety limit is even lower. It also seems to definitively limit the RF power at 50 cm and 913 MHz to 158 mW. (I misread units here, it's 50mm not 50cm, hence the scorethrough)

So the questions here are: "Would this exclusion still apply if the transmitter were "portable" and not potentially mobile?" but mostly "Have Energous chosen SAR instead of MPE knowing they would fail MPE?"

Looks like lots of gaming the system is going on.

Unsafe Demo, Faked, or Something Else?
Last point: The IEEE Spectrum article has a Jan 2016 demonstration of their system charging via an antenna at 5 feet at 1.6 Watts, while in a Las Vegas hotel room with a journalist present. They state that 0.673 Watts is about 10% of power transmitted, so 7 Watts total or so. At 5.8 GHz the MPE limit for an iPhone X receiver would be about 100 mW and 500 mW RF received, "general public" and "controlled" respectively. This was a demonstration then that exceeds regulatory limits, and if we scale linearly from the approved system I'd guess the entire room exceeded the SAR safety limit. So did Energous give an unregulated demonstration that exceeded safety limits, was it faked, or were they otherwise somehow exempted?

Sunday, December 31, 2017

Yet More Energous

It's been a busy few days on the Energous front, and will likely stay that way with CES coming up, along with watching how their share price will fluctuate and if any more insiders have cashed in. We'll almost certainly see plenty of new information and revelations, which will come in a little at a time, and it's hard to judge if they should just be included as addenda or merit a post in themselves. My last post had a few additions to it since I first published it, and it got to the point where I'm going to regurgitate some of it in a new post. If you read that post really recently, there won't be too much new here for you.

Before I begin though, I just want to remind everyone that this is a system that needs a safety cutoff and an exclusion-zone larger than the operating-zone to charge your phone in about a week, at closer than 1 meter (if at all), if you hold it perfectly in alignment. Sounds amazing, doesn't it?

Energous have, until now, relied on ambiguity and vague promises which could not be argued with due to lack of information, but data is now public due to the FCC filing. This data now gives us the first concrete (though incomplete) numbers to show what those with an understanding of physics and RF have always suspected - there's nothing new or amazing here. Energous are not finding that "one weird trick" that bypasses the laws of physics, or have a Nobel-prize level discovery. The emperor really does have no clothes, but instead has an awesome marketing and PR department.

A summary of what's here:

1) Energous could increase the power delivered, but would then have to increase the size of the keep-out-zone, likely to room-scale for most reasonable charge rates. This is also dependent upon perfect receiver alignment.

2) Charge rates shown in the FCC report look to be for phone-sized objects. Move to wearables and the power delivered will drop, likely significantly.

3) The system has very poor beamforming capabilities and the point of highest power is not often at the target location. It is not a precision system, comforting when it can hurt you...

4) Some people are mistakenly reporting that the system transfers power at ~2.4GHz with a max 400 microWatts. This is the communications part of the system, not for power transfer.

5) The system shown in the FCC filings is vastly inferior in every regard to the promises from January 2015.

More Power!
Energous appear limited in how much power they transmit primarily due to the SAR restrictions, which they are currently at. The FCC data shows they are at 0.966W/kg at 50cm, while the limit is 1.6 W/kg. If we assume a measurement and manufacturing tolerance of 2 dB total (63%) then that takes the 0.966 to 1.58 W/kg - basically they are working at the limit, there's no more headroom here to expand.

What can get them more power at any given location is to extend the "keep-out-zone" further, essentially the distance from the transmitter at which the SAR value is around 0.97 W/kg. Now we are dealing with near-field effects so it's hard to say exactly, but let's for now say that the SAR power value increases linearly with the receiver power value. Let's increase the power at 90 cm from 30 mW to 45 mW - in this case the keep-out-zone moves to 75 cm and your phone still isn't charging. Now double to 60 mW and the zone is at 1 meter - you're standing inside the unsafe perimeter and the system will of course shut off, your charge rate is zero. And your phone wouldn't charge anyway. Now let's raise the power to 500 mW, the bare minimum to charge a phone, and the keep-out zone is now 8.3 meters - larger than the room you're in and probably the room next to it, and the one after that as well.

Depending on beamforming the exclusion zone may increase slower than that, but even under best case assumptions it's still expanding to room-sized danger zones for pretty pathetic charge rates.

No! You're not holding your phone correctly!
Also remember that these numbers in the FCC report are for a receiver in perfect alignment for the transmitter - rotate 90 degrees in two out of three axes and you get nothing. Even rotating in the other axis reduces power by around 20% at 50 cm. 

Consider how you stand and hold your phone while using it - likely at around 45 degrees to the floor. You'll probably lose a good 30% of power at least, not including what your hand might absorb instead. Now consider how you place your phone on a table when you're not using it - flat. With that orientation, you're getting close to the "nothing" for power delivery. Actually use your phone, and charge rate will vary considerably but the key thing is this - the numbers you see reported by Energous are as good as it will get, under perfect circumstances.

Low Power for Phones - Ideal for Wearables!
As the initial excitement of the Part 18 approval fades, it's becoming clear to even the most ardent Energous supporter that the power levels here are so low as to be useless for phone charging, even if they increase by near an order of magnitude. What I'm seeing though from the Energous faithful is grasping at "charging wearables" as the killer app for Energous. Unfortunately, that's just not going to happen either.

The receive antenna Energous use is likely a half-wave dipole antenna (think the bars in a TV antenna), and given wavelength at 913 MHz is 33cm, a half wavelength in free space is 16.5 cm (half wave dipole antennas are actually slightly shorter than the free space half wavelength). Given a phone is usually 10 to 14 cm long, the antenna will be close to that, not perfect but some dielectrics around it and it's close enough. Some info on effective antenna area is here.

Now look at your watch - how large is that? What's the size of an antenna you can put in there? It's much smaller, with a reduced size comes reduced power delivery, and at around 1 to 2 cm probably quite a reduction. Maybe they can use a patch antenna and get the size needed down with a high value dielectric? We'll conveniently forget that patch antenna are highly directional, even more than what is seen in the FCC test. In that case the patch impedance gets high, and the power gathered will drop (power is voltage squared divided by impedance). Here's an online tool for calculating patch antenna sizes and impedances - in this case it fits in a wearable, at around 16 by 24 by 2.0 mm, but at 4.5 kOhms will produce about 1.5% of the power of a standard 70 ohm half wave dipole antenna. Oh dear.

Then we have the orientation issue - this thing is on your wrist or body, right? How do you ensure perfect orientation to get the power needed? Good luck there.

AirPods have a 1.5 Wh battery - standard perfectly at the 50 cm danger-zone limit and if you get the maximum 100 mW they'll charge in 15 hours. Except they won't, you'll get a fraction of that, and if you move the system shuts off.

So no, wearables aren't going to cut it for the huge market either.

Where's the Power Going?
When using a phased array to send power with precision, you ideally want a large grid of transmitters spaced half a wavelength apart, many many wavelengths total on each side, and a target far enough to be in the farfield (many wavelengths away). At 913 MHz, Energous have a line of only 12 antenna, spaced 0.2 of a wavelength apart, about 2.5 by 0.2 wavelengths on each side, and a target barely 2 wavelengths away. It's an awful design if you want to try to control where the beam goes, and you can see that in their own beamplots. The star in the image below is where the power is supposed to be beamed - does this image fill you with confidence as to what's getting powered?


This arrangement might have been enough if they could operate at 5.8 GHz and wavelengths were over 6 times smaller - but the FCC killed that, as no doubt the system wrecked any wWiFi in the vicinity.

Bottom line - this thing sends power everywhere and there is no precision about it. IMO it's a brute force attempt to simply get FCC approval under Part 18 and damn the practicality.

The 2.4GHz Band is for Communications, Not Power
I'm seeing quite a few people refer to the 2.4GHz band Part 15 approval that was granted (in addition to the Part 18 approval for 913 MHz) where maximum power of 0.4 mW (400 millionths of a Watt) is stated. This is not for power transfer, this is Energous getting the communications component of the system approved.


They state they use the 2.4GHz band, Bluetooth LE, for the receiver to communicate to the transmitter that at least 30 mW is being received to continue power. It is not the maximum power transferred - as much as Energous send out tiny amounts of power, this isn't the number to be looking at.

Diminished Expectations
Energous launched with the promise of charging multiple devices, at up to 15 feet, at multiple Watts. Here's part of their January 2015 media blitz:

A new wireless power “router” being shown at CES can charge multiple devices in a 15-foot radius.

The two-tone rectangular box you see mounted on the wall up above is a WattUp transmitter from the wireless power people at Energous. WattUp is capable of delivering .25W to 12 devices or 4W to up to four devices (up to five feet away, dropping to 1W at 15 feet) at the same time, and it’s smart about how it does it.

Inside the “router” there’s a Bluetooth module. It sniffs out compatible devices and helps establish connections to them. Once they’re connected, power is beamed out over frequencies in the 5.7-5.8GHz range, but it doesn’t just constantly blast devices with RF power packets.


Here is a brief summary of the results of the amount of actual power delivered to a device at varying distances with a single WattUp transmitter. Power received at zero to five feet measured 5.55 watts compared to our targeted performance of 4 watts. Power received at five to 10 feet measured 3.74 watts compared to our targeted performance of 2 watts and power received at 10 to 15 feet measured 1.06 watts compared to our targeted performance of 1 watt.

5.5 Watts compared to around 100 mW (at best)? Only a factor of 55 to 165 off after a further 2 years of work. Talk about diminished expectations. How can the bulls continue to support Energous after such a letdown? I guess it's better to continue to support than admit you were bamboozled by them.

Did they actually get that amount of power transferred? It's possible, you just have to be damn sure the transmitter is in a Faraday cage or you're a looooong way from it when it's switch on. Put those power numbers into the SAR danger-zone distance and you're looking at 10's of meters, and most likely polluting the surrounding spectrum outside the 902 to 928 MHz range in violation of FCC Part 18.305. I hope their staff weren't exposed to that!

Until the next post, take care, and Happy New Year to all.