RF MEMS Switch Startup Raises $44M to Expand Capacity

Menlo Micro, a pioneer in miniature RF MEMS switches, has raised $44 million in a Series B round of funding. Most of the money will be used to significantly increase production capacity of what the company refers to as the “ideal switch.” A spin-off from GE Ventures four years ago, the company has been refining the process that GE had been working on for some 12 years. Menlo Micro has already sampled devices to companies in the wireless communications, aerospace and defence sectors for deployment in, for instance, base stations, phased array radars, antennas, radio heads and military radios. The devices will be targeted at wireless infrastructure makers focusing on 5G. According to Chris Giovanniello, one of the co-founders and senior vice president at Menlo, “the key to the whole process is being able to make moving actuators that are truly robust.”

Talking to EE Times, Giavanniello said perhaps one of the toughest challenges was to devise an electrically conductive alloy that could withstand huge numbers of bending and unbending cycles. “The contact material used is also of vital importance for making the devices ultra reliable,” he stressed. Giovanniello would not reveal what the material is, but noted there is some gold in the alloy that is now being used. The metal-to-metal contact switch is constructed on a fully-isolating glass substrate and shrunk down to the form-factor of a solid-state device. He also revealed the devices will be made at a specialist MEMS foundry run by Swedish group Silex Microsystems, at a facility in Jarfalla near Stockholm. “We have been partnering with them for some time, and to meet our special requirements they had to add some new gear for the process.” The devices will be packaged by Corning, with whom the company has also partnered right from the start and which supplies the base material. The packaging process is based on Corning’s advanced Through Glass Via (TGV) technology. The process is said to allow Menlo to shrink the size of its products by some 60 per-cent compared with traditional wire-bond packaging. Giovanniello likens the digital micro-switch  technology to one that combines many of the important features of electromechanical relay switches (such as extremely low leakage and resistance, as well as very high linearity) with the vital advantages of semiconductor switches (for instance very high reliability , small size and ruggedness). “Others have tried in the past to get over the line with such a technology, but none have really succeeded. Our achievement owes a lot to GE’s long term R&D in this area,” Giovanniello told EE Times. “They have always been, and still are, very strong in high temperature, high voltage and high power industrial requirements, and we have built on that know-how, and adapted it to other applications. “ Early backers of the company in 2016 included Corning, GE Ventures, Microsemi Corp. and Paladin Capital Group. This week’s Series B funding, which brings the total investment in Menlo to $75 million, involves 40 North Ventures, Pica, Paladin Capital, Vertical Venture Partners and Future Shape. Tony Fadell, one of the founders of Nest, is a Principal at Future Shape.

Giovanniello said the funds will also be used to expand the company’s head-count from the existing 35, with immediate opportunities for both design and reliability engineers. But the majority of the money will allow the company to scale up production to over 100,000 units per month by the end of this year, and millions per month next year. Another target is to exploit opportunities in the test and measurement sector, “where there is an amazing volume of signal switching going on so it’s ideal for our miniature RF MEMS switch.” The switches typically measure 50 by 50 micrometers and comprise hundreds of elements in a single package. Unlike a typical relay, where actuation is triggered by an electromagnet, Menlo’s RF MEMS switches use a simple DC voltage in the 50-100V range to generate a static electric field that pulls the beam to the contact. Menlo says it has sampled products to over 30 “lead customers” that includes developers of 5G network infrastructure, advanced aerospace systems, high power RF and defence applications. Asked whether Menlo has any customers in the mobile handsets or tablets business, Giovanniello said while these are possible use cases, “we have decided not to go after that market directly –you need huge volumes there and it’s a much more aggressive cost structure. We are having discussions with others about potential licensing deals for the consumer marketplace.” Another start-up that has developed RF MEMS switches specifically to target that market, Cavendish Kinetics, was acquired last October by Qorvo. And Analog Devices is also active in the field, and to date has targeted the T&M sector. Menlo Micro, based in Irvine, Calif., was included in the latest iteration of EE Times’  Silicon 100.