Duplexer Designed on the Basis of Microstrip Filters Using High Dielectric Constant Substrates

摘要

A microstrip duplexer for a modification of a PCS communication system operating at frequencies of 1.84-1.87 and 1.75—1.78 GHz is described. The duplexer containing microstrip bandpass filters on high dielectric constant substrates (ε_r = 92) are compared with duplexers manufactured on microwave ceramic materials with high values ofε_ r. The microstrip bandpass filters use stepped-impedance resonators placed one near another with a gap of 0.1 —0.2 mm. It is shown that the microstrip duplexer has slightly lower insertion loss and occupies smaller volume than a duplexer using coaxial dielectric resonators having a rectangular cross section of 3 × 3 mm and ε_r = 92.