Author Topic: Multi-Gigabit Wireless Link using W-Band Phased Array Chipset  (Read 7371 times)

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Offline Hugoneus

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Hi everyone,

I have been busy with work and the MTT conference. Since I haven't had a chance to release a video, I thought I would let you know what I have been busy doing.

We had a live demo of a wireless link setup at MTT during our presentation which is capable of establishing a link (beyond) 32Gb/s at a carrier of 92GHz using two polarization. This uses the phased array chipset that I designed at Bell Labs. Each chipset has 16RX/4TX or 16TX/4RX phased array elements with up- and down-converters, integrated PLL, various calibration, self-test, etc. Two dies are flip-chipped directly onto PCB (die-on-PCB) with the phased array antennas integrated onto the PCB. This is no easy task at 92GHz! The EIRP at 90GHz is about 34dBm which is a record in itself at W-band.

I can try answering some questions as long as it is within released information about this project.
« Last Edit: June 03, 2015, 06:14:22 pm by Hugoneus »
Shahriar Shahramian
The Signal Path Video Blog
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Offline R_G_B_

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Re: 32Gb/s Wireless Link using W-Band Phased Array Chipset
« Reply #1 on: June 02, 2015, 09:16:38 pm »
Can you combine this technique with other diversity techniques to improve the speed much  further than 32Gb/s

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Offline ConKbot

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Re: 32Gb/s Wireless Link using W-Band Phased Array Chipset
« Reply #2 on: June 02, 2015, 10:30:46 pm »
Sounds very interesting! What sort of stimulation software is being used with this? I'm assuming this is to the point where even on die interconnects are controlled impedance? Any laser trimming or is the stimulation and fabrication good enough that it's ready to go after dicing? could on die antennas (patch?) Be a possiblity in the future? Hows the 3rd harmonic on the transmitter?  ;) ;D
« Last Edit: June 02, 2015, 10:40:38 pm by ConKbot »
 

Offline Lukas

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Re: 32Gb/s Wireless Link using W-Band Phased Array Chipset
« Reply #3 on: June 02, 2015, 10:54:15 pm »
Some questions:
How do you get data in/out of the chips?
What material is the chip made out of?
What modulation does it use / what's the modulation bandwidth?
What's the phased array stuff used for? Spatial multiplexing/MIMO or just to get the radiation pattern right?
Was the the chip first time right?
Is there a paper/publication?
 

Offline Hugoneus

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Re: 32Gb/s Wireless Link using W-Band Phased Array Chipset
« Reply #4 on: June 02, 2015, 11:21:46 pm »
Some answers to your questions:

The IC is designed in Cadence. It is a SiGe BiCMOS process with fT/fMAX of about 240GHz/270GHz.
The interface to the IC is baseband I/Q with up to 7.5GHz of bandwidth per side. (15GHz of RF bandwidth).
The modulation is adaptive and depends on the link quality. This is controlled by the modem ranging using various QAM.
Phased array is used for spatial beam forming.
There is a paper, it is published at RFIC 2015 which was held last month.
Shahriar Shahramian
The Signal Path Video Blog
www.TheSignalPath.com
 

Online Howardlong

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Re: 32Gb/s Wireless Link using W-Band Phased Array Chipset
« Reply #5 on: June 02, 2015, 11:31:33 pm »
Am I right to assume that this is for point to point links and that the phased arrays are fixed, i.e. no clever dynamic beam steering?

I had enough trouble building WR42 waveguide filters connected to LO, mixer and 30dBm amp 15 years ago for narrowband K band, let alone the sort of stuff you're doing. I guess waveguide's a bit old fashioned these days.
 

Offline Dago

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Re: 32Gb/s Wireless Link using W-Band Phased Array Chipset
« Reply #6 on: June 03, 2015, 05:02:50 am »
Sounds tremendously interesting! I've always wondered what you do for work. I've also recently been very interested in microwave stuff (currently building a FMCW radar).

Do you have any pictures of the system/PCB and could you share them?
Come and check my projects at http://www.dgkelectronics.com ! I also tweet as https://twitter.com/DGKelectronics
 

Offline Hugoneus

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Re: 32Gb/s Wireless Link using W-Band Phased Array Chipset
« Reply #7 on: June 03, 2015, 05:19:35 am »
Am I right to assume that this is for point to point links and that the phased arrays are fixed, i.e. no clever dynamic beam steering?
I had enough trouble building WR42 waveguide filters connected to LO, mixer and 30dBm amp 15 years ago for narrowband K band, let alone the sort of stuff you're doing. I guess waveguide's a bit old fashioned these days.

Beam steering algorithms are handled by the modem and often at the firmware level. :)
Shahriar Shahramian
The Signal Path Video Blog
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Offline Hugoneus

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Re: 32Gb/s Wireless Link using W-Band Phased Array Chipset
« Reply #8 on: June 03, 2015, 05:20:54 am »
Sounds tremendously interesting! I've always wondered what you do for work. I've also recently been very interested in microwave stuff (currently building a FMCW radar).
Do you have any pictures of the system/PCB and could you share them?

FMCW at what frequency?

Unfortunately the PCB photo isn't released yet, although I did show it during the conference presentation which is not distributed.
Shahriar Shahramian
The Signal Path Video Blog
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Online coppice

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Re: 32Gb/s Wireless Link using W-Band Phased Array Chipset
« Reply #9 on: June 03, 2015, 05:35:08 am »
Sounds tremendously interesting! I've always wondered what you do for work. I've also recently been very interested in microwave stuff (currently building a FMCW radar).

Do you have any pictures of the system/PCB and could you share them?
Is FMCW (or FMICW) still an interesting kind of radar to build these days?
 

Offline Dago

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Re: 32Gb/s Wireless Link using W-Band Phased Array Chipset
« Reply #10 on: June 03, 2015, 07:09:47 am »
Sounds tremendously interesting! I've always wondered what you do for work. I've also recently been very interested in microwave stuff (currently building a FMCW radar).
Do you have any pictures of the system/PCB and could you share them?

FMCW at what frequency?

Unfortunately the PCB photo isn't released yet, although I did show it during the conference presentation which is not distributed.

It is for 4.2-4.4 GHz altimeter band. By changing the VCO it would be easy to use it for 2.45 or 5.8 GHz too (just need to redesign the bandpass filter and swap the VCO) but the noise levels are very high and bandwidth is very low on those ISM bands. Also have lots of stuff for a 10 GHz YIG-oscillator based one.

A pic of the PLL+VCO board (PLL not locked yet): http://www.dgkelectronics.com/storage/electronics/fmcw_radar/vco_synth/pll_vco_working.jpg
Hairpin bandpass filter: http://www.dgkelectronics.com/storage/electronics/fmcw_radar/hairpin_filter/hairpin_filter_v2.jpg

Sounds tremendously interesting! I've always wondered what you do for work. I've also recently been very interested in microwave stuff (currently building a FMCW radar).

Do you have any pictures of the system/PCB and could you share them?
Is FMCW (or FMICW) still an interesting kind of radar to build these days?

I've found it fascinating. Involves lots of system level design, RF design, analog design, digital (embedded) stuff, software work (embedded and desktop)...

Question for Shahriar: How long did this project last? Maybe even split to design phase, prototyping phase etc.
« Last Edit: June 03, 2015, 07:12:27 am by Dago »
Come and check my projects at http://www.dgkelectronics.com ! I also tweet as https://twitter.com/DGKelectronics
 

Offline daqq

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Re: 32Gb/s Wireless Link using W-Band Phased Array Chipset
« Reply #11 on: June 03, 2015, 11:58:05 am »
This area of electronics is a completely amazing and alien realm for me...

What kind of spacial/length/time tolerance can you afford in such systems?
Believe it or not, pointy haired people do exist!
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Online nfmax

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Re: 32Gb/s Wireless Link using W-Band Phased Array Chipset
« Reply #12 on: June 03, 2015, 01:54:19 pm »
Are you using any sort of adaptation in the beam-steering, to cope with mechanical tolerances or temperature-dependent changes in phase shift, or is it a one-time set-up?
 

Offline Hugoneus

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Re: 32Gb/s Wireless Link using W-Band Phased Array Chipset
« Reply #13 on: June 03, 2015, 05:09:56 pm »

Question for Shahriar: How long did this project last? Maybe even split to design phase, prototyping phase etc.

Great work!

The project took about 1 year from transistor circuit design to demonstration.
Shahriar Shahramian
The Signal Path Video Blog
www.TheSignalPath.com
 

Online Marco

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Re: 32Gb/s Wireless Link using W-Band Phased Array Chipset
« Reply #14 on: June 03, 2015, 05:22:45 pm »
How much useful bandwidth remains if it has to use a bounce off another surface?
 

Offline Hugoneus

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Re: 32Gb/s Wireless Link using W-Band Phased Array Chipset
« Reply #15 on: June 03, 2015, 06:13:44 pm »
How much useful bandwidth remains if it has to use a bounce off another surface?

A couple of issues arise. The coherent bandwidth may be affected as well as multipath may cause fading at certain frequencies. There is also the issue of polarization scrambling due to reflection. All of these effects would be addressed at the modem layer.
Shahriar Shahramian
The Signal Path Video Blog
www.TheSignalPath.com
 

Offline vaualbus

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Re: 32Gb/s Wireless Link using W-Band Phased Array Chipset
« Reply #16 on: June 03, 2015, 09:11:45 pm »
How much useful bandwidth remains if it has to use a bounce off another surface?

A couple of issues arise. The coherent bandwidth may be affected as well as multipath may cause fading at certain frequencies. There is also the issue of polarization scrambling due to reflection. All of these effects would be addressed at the modem layer.

So your team/you have also work on some algorithm for the modem layer?
The project is similar to the one you post a photo a while back on the blog?
 

Offline rfdave#gmail.com

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Re: Multi-Gigabit Wireless Link using W-Band Phased Array Chipset
« Reply #17 on: June 04, 2015, 02:47:22 am »
I saw you there talking to the Rohde & Schwartz guys!
 

Offline Hugoneus

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Re: Multi-Gigabit Wireless Link using W-Band Phased Array Chipset
« Reply #18 on: June 04, 2015, 10:48:21 pm »
I saw you there talking to the Rohde & Schwartz guys!

I wish you had come and said hello! :)
Shahriar Shahramian
The Signal Path Video Blog
www.TheSignalPath.com
 

Offline R_G_B_

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Re: Multi-Gigabit Wireless Link using W-Band Phased Array Chipset
« Reply #19 on: June 05, 2015, 04:45:39 pm »
What type of forward error correction are you using?

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Offline rfdave#gmail.com

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Re: Multi-Gigabit Wireless Link using W-Band Phased Array Chipset
« Reply #20 on: June 08, 2015, 01:14:09 am »
I saw you there talking to the Rohde & Schwartz guys!

I wish you had come and said hello! :)

You looked like you were having a good discussion. Maybe next conference, I'll introduce myself.
 


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