APMC2010

MEMS devices have been expected to provide a major impact on RF architectures by reducing size and power dissipation, and adding new functions, such as reconfigurability. Because filters and switches are key devices for RF-MEMS utilization, they are selected to be present in this work shop.

The first and second talks are related to filters. The first one will present FBAR technology that has been widely used as filters and duplexers in the mobile phone. It also presents a coupled resonator filter that shows promise as a low phase noise device with tunability for VCO applications.

The second talk will present a methodology for designing and implementing tunable cavity-based RF-MEMS filters. The filters are based on evanescent-mode cavities that can be tuned by MEMS diaphragms appropriately placed over their capacitive posts. Analog tuning ratios of over 2:1 can be realized in this technique while maintaining a quality factor above 400-650.

The third and last talks are related to switches. The third one will present a unique RF-MEMS switch. The original mechanical structure based on a simply supported membrane enhances reliability by active restoring force and controlled positive/negative out of plane moving. Detailed results and advantages will be exposed concerning hot switching and lifetime. The last talk will present a commercialized ohmic contact RF MEMS SPDT switch, which has a low insertion loss of 1.0 dB and a high isolation of 40 dB, up to 10 GHz, and is packaged in 5.2x3.0x1.8 mm³. The technology developed for the switch will be presented.

Multi-Input Multi-Output (MIMO) is one of the hottest technologies for mobile radio systems. In order to evaluate the performance of MIMO terminal accurately, we must use actual antennas mounted on the mobile terminal in actual multipath-rich propagation environments.

There are two types of OTA (Over-The-Air) schemes to create the environments equivalent to actual multipath-rich propagation environments in a test bed. One is a radio echoic chamber named "reverberation chamber" surrounded by 6-plate metallic walls. The other is a fading emulator which arranges a number of actual radiation antennas representing scattering objects. Both schemes have merits and demerits with regard to their accuracy, feasibility and cost for examples.

In this workshop, we present two types of OTA schemes from various points of view and show the performances of MIMO terminal which were obtained in a test bed by using the OTA schemes and in a real field test.