Design and Characterization of a RF Frequency-Hopping Filter

摘要

Integrated RF filters in future radio applications are expected to be reconfigurable to support multifunction radio capabilities and low power for mobile applications. The incorporation of MEMS passives in integrated RF filters can help achieve these goals. MEMS capacitors can switch between a minimum and maximum capacitance value, giving reconfigurable capability to an LCfilter. Micromachining inductors improves quality factor, potentially enabling integration of an allpassive LC-filter with zero power consumption. Several designs of a passive, RF, reconfigurable filter topology have been explored. The LC-filter topology is a pi-network. The filters have been designed, simulated, fabricated, and tested. A reconfiguration range as high as 850 MHz has been demonstrated. Inductors used in these designs have been characterized with test structure measurements, lumped parameter models, and fast method-of-moments solver models. Inductor characterization has provided insight into quality factor improvement due to micromachining and quality factor for various inductor geometries. This project serves as one of the first attempts at integrating several MEMS passives together to form an electronic circuit. Future directions in this work include new filter topologies, improved design choices based on passive characterization results and wider reconfigurable ranges.