Liquid crystal polymer-based integrated passive development for RF applications

A Liquid Crystal Polymer (LCP) based multilayer packaging process is presented for RF/microwave applications. LCP is gaining increasing interest as a choice technology in the packaging community due to its superior thermal and electrical properties including low loss, low dielectric constant and low CTE characteristics. For the first time, we present a thorough study of the design, model, and measurement of integrated passives using LCP. A coplanar waveguide transmission line test structure demonstrates an insertion loss of 0.35 dB at 23 GHz and a return loss better than 15 dB to 30 GHz. Quality factors (Q) in excess of 70 and a self resonance frequency (SRF) to 29 GHz have been achieved. A bandpass filter implementation is also demonstrated to realize a c band module. Advantages of passive integration using built up LCPs as opposed to multilayer organics are discussed.