Both companies will pursue MEMS tunable filters to improve reception and mitigate dropped calls, thereby increasing performance and expanding capacity on NTT's mobile networks.

WiSpry's MEMS capacitor arrays allow RF applications to dynamically tune their circuitry to adapt to changing circumstances while a handset user moves about, touches the antenna portion of the case and encounters obstacles or reflections down urban canyons. Today, most tunable RF functions are set at the factory with discrete components, whereas putting those functions into a capacitor array allows microcontrollers to optimize performance in real time.

WiSpry (Irvine, Calif.) recently announced separate joint development deals with IBM in the U.S. and Infineon in Europe to develop tunable RF MEMS front-ends for cell phones. The terms of the deal with NTT DoCoMo (Tokyo) were not disclosed

The joint development effort will result in CMOS chips using RF MEMS that shrink the size, lower the cost and improve performance over the many discrete components required for RF filters today. Dynamic tuning of the filters as a handset user moves about, according to the companies, will making calls go through more smoothly thereby increasing the overall performance and expanding network capacity.