Noonen is a semiconductor veteran who has started to specialize in guiding startups. He has worked for many companies included spells in senior management with National Semiconductor, NXP Semiconductors, and Globalfoundries. Most recently he was with Silego Technology Inc. prior to its acquisition by Dialog Semiconductor in 2017 (see Dialog buys configurable mixed-signal IC pioneer).
I started the interview by asking Noonen if the Covid-19 pandemic had been a problem for startup MixComm. It had caused the cancellation of Mobile World Congress and turned the launch of MixComm's first product – the 'Summit 2629' 28GHz beamforming front-end IC for 5G cellular communications – in to a slightly lower key affair than it might have been (see Startup launches 5G front-end beamforming IC).
Lightning-quick to see the sales angle Noonen replied: "One thing we have learned from the pandemic is that communications infrastructure needs to be upgraded. 5G is exceedingly important." And that's what MixComm is betting on with its application of circuit design to a radio frequency silicon-on-insulator (RFSOI) manufacturing process.
Noonen pointed out that the company, although founded in 2017, is building on a legacy. "The company was co-founded by Dr Harish Krishnaswamy, a professor at Columbia University, and Frank Lane, previously a vice president of technology with Qualcomm. But the company leverages almost a decade of RF design advances made at the CoSMIC laboratory that was led by Professor Krishnaswamy.
Noonen observed that prior to that, the US Defense research agency DARPA had funded research into the RFSOI manufacturing process, which had been brought to realization by IBM, before the technology was passed to Globalfoundries in 2014.
With a 45nm RFSOI process to design to and exploit, MixComm has got to first product revenue with an equity investment of less than $10 million, Noonen said. "This is the best time to be a semiconductor entrepreneur if you can do it frugally. In the digital domain, it can cost $100 million to find out you've built the wrong chip," commented Noonen.
On the assumption that MixComm has built something approximating the right chip, where does the company's commercial advantage come from?
"It comes from that deep understanding of RFSOI acquired over many years and knowledge of the circuit architectures it supports," said Noonen.
RFSOI is a specialized planar process that can be used to make numerous RF chips such as high frequency switches and antenna tuners for smartphones. It is akin to fully-depleted silicon-on-insulator (FDSOI) with similar back-biasing options. Not only does it allow performance in silicon close to compound semiconductor devices but it supports integration in a similar manner to CMOS and on large diameter wafers.
As cellular communications move from 3G to 4G and on to 5G more and more carrier frequencies are being used. Simply adding additional gallium-arsenide piece parts is an expensive solution, Noonen said.
"RFSOI provides not only a tremendous Fmax but also things like [topologically] stacked power amplifiers. Allowing designers to stack multiple power amplifiers provides a breakthrough in output power. We are approaching III-V and wide-band-gap device performance with CMOS efficiency and integration opportunities," said Noonen.
He added that one of the pain points in 5G roll out is in the size of antenna arrays. When built with conventional technology they can be large, costly and unaesthetic. When there are numerous smaller cells, making 5G antennas unobtrusive is a key consideration. "Increasing the amplification from 60dBm to 70dBm can change the cost of coverage from $1.5 million per square kilometer to $500,000," Noonen said.
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