A Compact Broadband MEMS-Integrated Diversity System

A multidisciplinary-research effort encompassing compact broadband antenna design, indoor channel characterization, and an RF microelectromechanical-system (RF MEMS) technology with its application to a diversity system for indoor wireless communications is presented in this paper. We first introduce a coplanar waveguide-fed compact wideband antenna and characterize its impedance and radiation characteristics. The antenna has a 42% impedance bandwidth covering the frequency band of 4–6 GHz. Subsequently, a series of experiments are conducted to characterize the diversity performance of a system using three elements of the proposed antenna for nonline-of-sight indoor multipath environments. From these experiments, we evaluate the performance of the diversity system by calculating power correlation coefficients, power imbalance, and diversity gain. Microwave-laminate-compatible RF MEMS process technology, which has been recently developed in the author's group, is used to construct a microelectromechanically switched pattern-diversity antenna on RT/Duroid5870 microwave laminate. Radiation and impedance characteristics of this antenna are provided, and its reconfigurability capabilities for mobile environment are discussed.