Q. Can you give us a brief history of Menlo Micro? When was the company founded and the objective behind it?
Menlo was founded when General Electric made the decision to spin out it’s unique high-power MEMS switch technology as a separate company in 2016. The technology was developed starting in 2004 when GE Industrial wished to explore the use of MEMS switches for high-current circuit breakers. By 2016, GE had deployed the technology in MRI machines and helped to spawn the creation of Menlo with the objective of scaling up the manufacturing to drive capacities higher and costs lower.
Q. Can you tell us more about the Switch Technology that Menlo Micro has Developed? How is it different from conventional Switch Technology?
Menlo has branded the unique process for making high-power MEMS contact switches as the “Ideal Switch”. It is very different from other conventional switch technologies in a few key ways. While our devices are mechanical contact switches and have low losses and power handling associated with conventional mechanical relays, they are 30-50x smaller volume. The smaller size and smaller mass then allow us to have switching times 1000x faster than conventional mechanical relays, and the innovations in custom alloys enable a 1000x longer lifetime. When compared to certain solid-state switching technologies, our Ideal Switch will have lower losses, power consumption, and much higher linearity. This is due to the fact that we use true metal “conductors” in our signal path, rather than a “semi-conductor” which has voltage drop, leakage currents, and non-linear effects which can degrade the performance.
Q. Over the years, there has been a lot of talk about switches based on RF MEMS, however, most if not all of the companies stopped development or shut down. What has Menlo Micro done differently?
Menlo has benefited from over a decade of research by General Electric into the fundamental material science of MEMS switches. GE’s ability to develop new processes and new alloys put them in a unique position to address some of the key challenges which have made it difficult to achieve a reliable product and commercial success in the past. The fact that our Ideal Switch technology has shipped over 100k pieces into high-reliability medical instrumentation is a testament to the advances in MEMS switch reliability.
Q. Up to what frequency can this Switch Technology work?
We are releasing new products in 2019 which operate up to 20GHz. We currently have designs on our roadmap that will allow us to push up to 40GHz in the near future. The core switch technology itself has been characterized up to 50GHz so we have a lot of room to grow.
Q. What are the applications for your RF Switch Technology?
Beyond the Medical equipment applications demonstrated by GE, we are getting a lot of traction with applications in Military Radio, Test & Measurement, and also 5G Wireless Infrastructure. We are especially well-suited for applications where insertion loss and linearity are critical to overall RF system design, (as compared to traditional solid-state technologies) as well as situations where size, weight, and power (SWaP) are critical design parameters.
Q. How does the RF Mems technology compare to RF SOI Base Switches?
It depends on the specific switch that you compare to. Again, the fundamental difference between one of Menlo’s Ideal Switch products and an SOI switch are the losses and linearity. These can be traced back to a key figure of merit for switches called Ron*Coff. This value is the On-resistance when the switch is turned on X the Off-capacitance when the switch is turned off. Given our metal-to-metal contact, glass insulating substrate, and air-gap open circuit, we have demonstrated Ron*Coff 5x to 10x lower than SOI. In addition, our switches have inherently higher breakdown voltages than SOI switches and so can handle a lot more power. Of course, SOI switches are manufactured in extremely high volumes today, so they are extremely low cost, and that is something where we will improve over the next few years as our volumes increase.
Q. How does the Menlo Micro Technology Compare to PIN and GaN for High Power Applications?
In general, we are able to handle more channels and more power in a smaller form factor than PIN and GaN technology, while maintaining linearity that is 30dB to 40dB better. We also can operate our switches at relatively high temperatures with little impact on electrical performance. This is thanks to the low-loss metal contacts which generate very little self-heating. In addition, we can operate down to DC since it is a metal contact, and very broadband. Finally, in the case of PIN diodes, the biasing networks can be quite complicated and require a lot of current to actuate the switches. Since we are electrostatically actuated, we consume a lot less current and generate a lot less heat. This can be critical for reducing size, weight, and power which is sometimes dominated by thermal management concerns.
Q. Can you tell us more about how this technology has evolved over the last few years? What is the future roadmap for this technology?
Since we spun out of GE in Dec 2016 we have been focused on introducing new packaging technologies, in partnership with our investor, Corning, who has helped us bring a truly unique semiconductor package to the market, Through-Glass-Via (TGV). This allows us to shrink the size of our products by over 50% from where we were 2 years ago, and that helps to improve the RF performance as well. Our future roadmap will have us pushing in two directions: (1) to increase performance and push to higher frequencies to cover emerging applications in mmWave bands, and (2) decrease cost per channel by increasing switch density and driving our manufacturing to scale.
Q. Has Menlo Micro Started Shipping switches based on this new technology? When did you start? Who are some customers that use this switching technology?
Yes, we started shipped products into the Medical Instrumentation market, for GE Healthcare MRI systems, in 2015. Beyond the medical market, we are focused on applications in Aerospace & Defense, Test & Measurement, and Commercial Wireless Infrastructure. We can’t comment publicly on the specific customers we are working with but we have over 20 customers currently designing high-performance RF subsystems with our latest products.
