Thanks for the great write-up! I am a bit confused on why SiTime's programmability is unique. Seems like they just packaged fraction-N PLLs and their MEMS oscillator together. In principle, TI could package their BAW resonator with PLL and achieve the same programmability. Sure, fractional-N PLL is hard to set up and work with compared to integer-N PLL, but it is a very mature technology. It seems like SiTime's edge is still PCB space (?).
Also from the picture, the photonic grating coupler used by Ayar labs is not really a phased array. It is a pretty standard periodic structure for any photonic testing with fiber. The grating area is small (~10 um^2) and the distance between the fiber and grating coupler is also quite small (<10 um), as such the coupling efficiency depends on the near-field distribution of the optics. Small fabrication disorder doesn't really matter.
Thanks for the write up. Alphawave Semi has invested heavily in Coherent-lite to compete with Marvell/Ciena in networking campuses and increasingly within the datacentres themselves. I wonder how others see this coherent-lite adoption playing out especially at shorter distances. You also get custom silicon, chiplets and a full portfolio of PHY, controller and subsystem IP (which Siemens EDA is now throwing their weight behind). I think they are a much better prospect than the likes of Credo not least because, just as with ARM previously, the London market has no idea how to value them you get it for 1/10th of the price. I'm surprised they haven't had a mention in any of your articles so far, very interested to hear anyone's opinion on them.
Thank you for continued great education. 2 questions. 1) Impact of CPO on transceiver players. 2) why is BRCM using TSMC for CPO if its process is bad.
Just to note, in RF an "un-steered phased array" of this style (serial elements, vs corporate feed) is very common, we just call it a "travelling wave antenna". Typically this is a waveguide with slots cut into it. The only thing to be aware of is it's inherently a spatial-frequency filter, i.e. the beam direction is a function of frequency.
Thanks for this great overview! I fully agree with the concept that optical interconnects are the future for any setup requiring very high bandwidth that is further than (at most) several inches apart. I am especially excited by on-chip/on-package conversions of signals, those would (will) revolutionize high-performance computing. Just imagine being able to create large HPC clusters with individual sites several miles apart, with essentially no increase in latencies.
The question is indeed who'll get there first with solutions that make both technical and financial sense.
Thanks for the great write-up! I am a bit confused on why SiTime's programmability is unique. Seems like they just packaged fraction-N PLLs and their MEMS oscillator together. In principle, TI could package their BAW resonator with PLL and achieve the same programmability. Sure, fractional-N PLL is hard to set up and work with compared to integer-N PLL, but it is a very mature technology. It seems like SiTime's edge is still PCB space (?).
Also from the picture, the photonic grating coupler used by Ayar labs is not really a phased array. It is a pretty standard periodic structure for any photonic testing with fiber. The grating area is small (~10 um^2) and the distance between the fiber and grating coupler is also quite small (<10 um), as such the coupling efficiency depends on the near-field distribution of the optics. Small fabrication disorder doesn't really matter.
Thanks for the write up. Alphawave Semi has invested heavily in Coherent-lite to compete with Marvell/Ciena in networking campuses and increasingly within the datacentres themselves. I wonder how others see this coherent-lite adoption playing out especially at shorter distances. You also get custom silicon, chiplets and a full portfolio of PHY, controller and subsystem IP (which Siemens EDA is now throwing their weight behind). I think they are a much better prospect than the likes of Credo not least because, just as with ARM previously, the London market has no idea how to value them you get it for 1/10th of the price. I'm surprised they haven't had a mention in any of your articles so far, very interested to hear anyone's opinion on them.
Thank you for continued great education. 2 questions. 1) Impact of CPO on transceiver players. 2) why is BRCM using TSMC for CPO if its process is bad.
Just to note, in RF an "un-steered phased array" of this style (serial elements, vs corporate feed) is very common, we just call it a "travelling wave antenna". Typically this is a waveguide with slots cut into it. The only thing to be aware of is it's inherently a spatial-frequency filter, i.e. the beam direction is a function of frequency.
> As a wise CEO once said, plan B is to drink your own urine.
gahaha
Thanks for this great overview! I fully agree with the concept that optical interconnects are the future for any setup requiring very high bandwidth that is further than (at most) several inches apart. I am especially excited by on-chip/on-package conversions of signals, those would (will) revolutionize high-performance computing. Just imagine being able to create large HPC clusters with individual sites several miles apart, with essentially no increase in latencies.
The question is indeed who'll get there first with solutions that make both technical and financial sense.