Symmetrical Metal-contact RF MEMS Switch from UC San Diego: Art and Engineering
San Diego, CA, April 16, 2014 --If you’ve seen the images associated with Research Expo 2014 at the UC San Diego Jacobs School of Engineering, you’ve been looking at a symmetric and compact circular switch design. It’s the basis for single-pole multiple-throw RF MEMS (Radio Frequency Micro-Electro-Mechanical-Systems) switches being developed in the labs of electrical engineering professor Gabriel Rebeiz here at the Jacobs School of Engineering. Rebeiz is the recipient of the 2014 IEEE Daniel E. Noble Award for Emerging Technologies, “for pioneering contributions enabling commercialization of RF MEMS technology and tunable micro- and millimeter-wave systems.”
|Research Expo 2014|
The circular topology allows the design of multiple-throw switches with any number of ports by determining the proper angle and radius. In addition, the designed switch can achieve the exact same RF performance from the input port to any output port due to its symmetric configurations.
The circular switch serves to illustrate Research Expo 2014, which is an annual event in which 200 engineering graduate students from all six departments of the UC San Diego Jacobs School of Engineering present their research at a poster session. Research Expo also includes six fast-paced engineering tech talks from faculty and a networking reception.
Research Expo offers the chance for engineers, project scientists, recruiters and potential investors to connect with the talent and cutting-edge research of the Jacobs School of Engineering.
Research Expo is Thursday afternoon April 17 from 2pm to 6pm on the UC San Diego campus. On-site registration is availalbe.
Single-pole Multiple-throw Switches
Single-pole multiple-throw switches are broadly utilized in modern communication systems requiring operation at 3G/4G standards such as cell phones and tablets. This area has been dominated by solid-state switches such as silicon SOI and SOS switches due to their high-count SPNT switches (N=8-16). SOI/SOS SPNT switches, while having excellent performance up to 2.7 GHz, quickly fail in terms of insertion loss and isolation above 3 GHz due to their inherent large off-state capacitance and low-pass tuning networks.
In contrast, RF MEMS metal-contact switches have lower insertion loss and higher isolation and linearity in comparison to SOI/SOS switches. Furthermore, RF MEMS switches can be operated up to 10 GHz with a large number of ports, and are therefore useful for advanced 4G/LTE systems (up to 5 GHz), MIMO W-LAN (wireless local area networks), satellite switching networks, wideband (defense) radios and other applications.
Developing an RF MEMS switch capable of switching a large number of ports in a small chip area is important because area is directly proportional to cost in large-volume manufacturing processes.
Hyun-Ho “Joey” Yang, a post-doctoral researcher in the Telecom Integrated Antennas, Circuits, and Systems Group run by electrical engineering professor Gabriel Rebeiz generously provided the technical description of the switch design on which this article is based. Gabriel Rebeiz and his research team are part of the Electronic Circuits and Systems groupin the Department of Electrical and Computer Engineering at the UC San Diego Jacobs School of Engineering.
At Research Expo 2011, Chirag Patel from the Rebeiz group won the top prize– the Rudee Outstanding Poster Award – at Research Expo for work on RF MEMS metal-contact switches.
The circular-switch photo was taken by the Jacobs School’s Josh Knoff, as part of a photo shoot that yielded the cover image for the Winter 2013/2014 issue of the Jacobs School’s Pulse magazine. The cover story: RF MEMS possibilities for smartphones.