WSJ: Pros and Cons of Moving Above 100GHz — Circuits, Systems and Potential Applications

Presentation Abstract
The D-band frequency range is gaining attention for both radar and communication applications due to potential system miniaturization related to smaller wavelength and the possibility of having larger bandwidth. There is an ongoing frequency regulation activity at ETSI, ECC and FCC on standardization of new frequency bands, targeting bandwidth >10GHz. Large bandwidth is beneficial for radar to achieve good range resolution, while for communication applications one can achieve higher data-rates. Pushing operation frequencies even further beyond the D-band towards 300GHz may offer even more potentially large available unregulated bandwidth. However, these high operation frequencies reach the technological limits imposed by the available CMOS processes. Operating the transistors at frequencies beyond half of the achievable ft/fmax makes it very difficult to obtain sufficient gain and power from an amplifier stage. One possible solution would be to use III-V technologies, which offer ft/fmax frequencies by far exceeding those of advanced CMOS nodes. Still, the possibility of integrating the mm-wave front-end with the digital baseband on the same chip makes CMOS very attractive despite this mentioned drawback. Another challenge that comes at higher frequencies are the higher losses of the interconnects. The packaging possibilities. Realization of antennas (on-chip or in-package?). As well, much higher propagation losses make the link budget very challenging and make it very hard to reach ranging or communication over large distances. In this full-day workshop we will address exactly these questions: (a) does it make sense to go to frequencies above 100GHz? Or shall we stay in the comfort zone below 100GHz?; (b) for which applications does it makes sense at all?; (c) what are the circuit related challenges in silicon-based technologies and how can we solve them?; (d) what are the challenges not only to build an SoC, but to actually build a system >100GHz?; (e) discuss emerging applications that might profit by very high frequencies. Level budget considerations for various mm-wave systems will be discussed. Fair and unbiased opinions will be given by experts. The workshop features distinguished speakers from leading companies and academia, who will present their view on mm-wave circuits >100GHz, as well as sharing their “best practice” on how to design mm-wave circuits. A brief concluding discussion will round-off the workshop to summarize the key learnings on the wide range of aspects presented during the day.