10 ms·
Low-cost 60GHZ phased array antenna
- lukeqsee 7y agoSince it’s in the 60GHz range, that means it would basically require line-of-sight to function, right? Not downplaying the significance, but I’m not sure we’ll get WiFi at 1.5km just yet because of it.
- C1sc0cat 7y agoCould be useful for backhaul though for mesh networks outdoors
- wil421 7y agoYou could use it to extend range to a large campus, stadium, race track, farm or even between two office builds in close proximity. It’s somewhat niche but there is a use case for short line of sight connection.
- penagwin 7y agoThese types of devices have existed for a while with a dish at least. You're right, at this frequency you need LOS and there's little forgiveness there. Current products don't really intend (to my knowledge) for you to connect a client directly to this antenna, rather they're meant for both to be in a fixed location properly aligned to each other, then they go to the access points for the clients. Like the other's mention, this is useful for many environments with multiple buildings, easy example is a shed out in your backyard. Obviously if you could run a copper/fiber connection out directly that'd be better, but these are for situations where you can't.
- dillonmckay 7y agoIs 60GHz band unlicensed in US and EU?
- monocasa 7y agoNot in the US at least.
- walrus01 7y ago60 GHz is unlicensed in the US. Bridgewave and others have been shipping 60 GHz band point to point outdoor radios since 2008. 71-86 GHz ("E band") is light licensed, which is easier and less costly to coordinate than the traditional 6/11/18/23 GHz FCC part 101 microwave bands.
- deleted 7y ago[deleted]
- jotm 7y agoI believe that's what he meant, not [licensed] in the US at least.
- joshvm 7y agoIsh in the UK, see http://static.ofcom.org.uk/static/spectrum/fat.html http://static.ofcom.org.uk/static/spectrum/fat.html Some ranges are usable for Industrial/Scientific/Medical (ISM), and there are exempt low power devices although I leave it as an exercise to the reader to find out which: https://www.ofcom.org.uk/__data/assets/pdf_file/0028/84970/ir-2030.pdf https://www.ofcom.org.uk/__data/assets/pdf_file/0028/84970/i... For example: IR2030/7/2, wideband transmission systems that are not fixed can be used up to 40dBm between 57-71GHz. Fixed systems are allowed, but not within 6km of certain sites. You can also use it for tank probing radar under various situations. One of them is MOD Hebrides which is a large closed area for weapon system testing, another is Castlemartin training area, and another near Luffenham (no idea about that one). Presumably it interferes with military radios and at least two of those sites are used with live ammunition, so probably it's a safety thing.
- asadkn 7y agoSays low-cost but anyone knows what exactly is "low cost" here?
- rkangel 7y agoWith the process technologies they're using, I'd guess 10s to 100s dollars.
- jandrese 7y agoFor a phased array antenna?
- rkangel 7y agoFor the antenna yes. Doesn't included the associated electronics to drive it.
- madengr 7y agoI'm betting the front-end chip is all CMOS, as opposed to SiGe, so it will be quite cheap (under $10 in volume). 16 TX elements at a total of 20 dBm transmit power is 8 dBm/element, which is feasible in CMOS. State of the art in CMOS is 9 dBm at 80 GHz. The antenna will be cheap too as there are number of spread spread glass laminates out now; I have used Rogers RO1200 for mmWave work. The only thing that may make it expensive is the air-gap construction, which they have probably done to increase the bandwidth. I would assume two laminates are needed.
- Robotbeat 7y agoSure, why not? It depends on the number of elements, of course, but at these frequencies, you can fabricate a LOT of elements for low cost because they're small. Perhaps even chip-scale integration is possible. $1/element is feasible for phased arrays.
- mNovak 7y ago
- jtbayly 7y agoYou can buy a set of pre-paired (configured) devices from Microtik for $195 that are 60Ghz 1Gbit full duplex that don't require any dish. I've used them, and they work well. (https://www.amazon.com/dp/B077992GG3 https://www.amazon.com/dp/B077992GG3) The difference here seems to be a substantial increase in distance. 1.5km is a lot more than the 100-200m promised by Microtik. Also, yes, any 60Ghz device is going to be line-of-sight only.
- 908B64B197 7y ago1.5KM makes 'wiring' a village possible from one relatively high structure, such as a church's bell tower.
- cozzyd 7y agoIn good weather...
- C1sc0cat 7y agoWell for PTP have a fallback 2.4 Ghz with a pair of polarised Yaggi's and jack the power up. What I mean by having a pair is have one channel vertically polarised and one channel horizontal double bandwidth
- doikor 7y agoLine of sight truly means line of sight with 60GHz. As a human standing in the way is enough to mess with the signal so would a flock of birds I guess.
- chrisseaton 7y agoDo flocks of birds regularly hover in one place for an extended period of time? Coming up with increasingly bizarre limitations here.
- tuco86 7y ago
- ldite 7y agoThis isn't all that new - I've lost the link to the press release, but this thing will also do 1Gbps+ at 1km: https://www.siversima.com/wp-content/uploads/product-brief-trx-bf01-20200220.pdf https://www.siversima.com/wp-content/uploads/product-brief-t...
- richk449 7y agoIs this just a passive phased array? I can’t electronically steer it, can I?
- madengr 7y agoNo, it's active. Assuming they are using their 16 channel chip: https://perasotech.com/x-series-products/ https://perasotech.com/x-series-products/ I'll bet it's two, 32 element arrays (one each TX and RX) composed of 2-element sub arrays.
- mNovak 7y agoWith 22dBi they're quoting, it'd have to be all Tx or all Rx. Unless they're conflating amplifier gain in there, which sometimes happens.
- madengr 7y agoThe block diagram didn’t show a switch, and the NF is 6 dB, so I figured it was separate. I have used the HMC-6301, which has about the same NF. The switches get quite lossy at mmWave.
- richk449 7y agoSo where it says support for 16 antennas, that means that there are 16 individual rf amplifiers, and the phase and amplitude of each channel is being set to do the beamforming? Can a user just put in 16 rf feeds and do the beam steering themself? If used in the standard form, can it do digital beamforming (send different info on different beams)?
- madengr 7y agoYes. Each PA probably has no more that 10 mW (assuming CMOS), but coherently added will yield over 100 mW EIRP. For RX the signal coherently adds, but the LNA for each channel has uncorrelated noise, so the RX SNR is not as good as a passive array (assuming zero feed loss). Probably other circuitry to keep all the channels calibrated. No, not in that chip. It has differential I & Q baseband I/O which are split and converted using a LO coherent to all the channels, then amplitude and phase shifted. No, that would require phase and amplitude weighting to be done at digital baseband. There are some other ICs with 4 channels to drive 4 element sub-arrays. These large MIMO arrays will have sub-arrays with RF amplitude and phase weighting, then each sub-array is fed with I & Q baseband with separate weighting.
- danesparza 7y agoIt can achieve that without a dish because (correct my math if I'm wrong) a full wavelength antenna for 60GHz is 0.1968 inches. So I'm pretty sure the silica includes the antenna.
- madengr 7y agoThe antenna is built on a separate substrate, I'm guessing a spread glass such as Rogers RO1200. You can do the aperture calculation here, which for a square aperture at 100% efficiency is 18x18 mm. It's probably more like 75% efficiency. https://www.everythingrf.com/rf-calculators/effective-antenna-aperture-calculator https://www.everythingrf.com/rf-calculators/effective-antenn...
- gene-h 7y agoUsing 60 GHz for communication at these distances is pretty strange because 60 GHz is strongly attenuated by the atmosphere. Not only that, but atmospheric attenuation peaks at 60 GHz because that's what oxygen absorbs[0]. Some military satellites even use 60 GHz for intersatellite links because it's highly attenuated by the atmosphere, making eavesdropping more difficult [0]https://en.wikipedia.org/wiki/Extremely_high_frequency#Propagation https://en.wikipedia.org/wiki/Extremely_high_frequency#Propa...
- danesparza 7y agoAgreed. 60GHz appears to be allocated for fixed inter-satellite communications (probably for this reason): https://transition.fcc.gov/oet/spectrum/table/fcctable.pdf https://transition.fcc.gov/oet/spectrum/table/fcctable.pdf
- peter_d_sherman 7y agoI read some of the above PDF... what's amazing to me is that a whole bunch of names of foreign countries pop-up over and over again in this document, specifically with assigned frequency ranges, as if the FCC is regulating frequency ranges in foreign countries... Before reading this, it seemed self-evident (to me) that the FCC's regulatory power does not extend to those foreign countries... Although, perhaps the FCC's regulatory powers do in fact extend to those countries via international agreements and/or treaties? Does someone know? How does that work?
- tssva 7y agoIf you re-read the document you will see that there is a note regarding the international frequency ranges indicating that they are taken from the 2016 edition of the ITU Radio Regulations.
- peter_d_sherman 7y agoInteresting! So ITU is sort of the international standards organization for radio frequency bands... makes sense!
- tus88 7y agoHow does that work when no Silicon runs at 60ghz? What can process the signal?
- tomxor 7y agoYou are thinking of big CPU clocks, this is not the speed of a single transistor switching, it is determined by whatever was accepted as the longest path of components for electricity to propagate through (think of a ripple adder as a simple example). You can have a much smaller separate clock and thus higher frequency for single purpose silicon when the path is significantly shorter. 60GHz here is talking about signal, you only need to create an oscillation at 60GHz not do fp multiply. There are various ways of doing so, but consider that it only takes three inverters to create a ring oscillator. As for the data - you don't need to fill the buffer at the speed which bits are sent, which is how you can interface with a lower frequency microcontroller, i.e the buffer is filled at a lower frequency but in large chunks i.e words. Someone with proper EE and signal processing knowledge will explain more accurately but that's the crude idea (components frequency vs clock).
- creatornator 7y agoNot sure if this is what you are getting at but high speed comms modulate a signal up from a lower frequency to a much higher carrier frequency for transmission. Then the receiver modulates back down to baseband (the original frequency before modulation). This can be done with discrete hardware, no need to do the DSP with a CPU that can't reach those clock speeds. It's one of the reasons your 5GHz WiFi doesn't actually have a 2.5Gbps bitrate (satisfying the Nyquist criterion), but something closer to 1.3Gbps. Source: graduate with MS EECE in Comms, Control, and Signal Processing in a couple months
- tomxor 7y ago> It's one of the reasons your 5GHz WiFi doesn't actually have a 2.5Gbps bitrate (satisfying the Nyquist criterion), but something closer to 1.3Gbps. Ah, this is not what I meant but just as relevant. I think you are essentially saying that you don't have to send as many bits per second that the signal frequency is capable of? I suppose that would satisfy any arguments that focus on bit throughput.
- hestefisk 7y agoThat’s Hz, isn’t it?