A Miniaturized Triple-Mode Microstrip Bandpass Filter

A Novel miniaturized triple-mode microstrip bandpass filter (BPF) using space mapping (SM) technique is presented in this paper. Three operating frequencies at 1.9 GHz, 2.14 GHz and 2.45 GHz are excited that are used for CDMA, WCDMA and RFID applications, respectively. In the proposed design, Substrate manufactured from RT_DURRIOD_5880 with dielectric constant of 2.21 and height of 20 mil that it's located between a radiation patch on the top and a ground plane on the bottom. The benefits of this resonator are small volume, integrated structure, high rejection level and low insertion loss in the passband. Therefore, the proposed novel design has a very small size (4 mm × 36 mm) compare with similar works. There is a close agreement between measurement and simulation results. The compact circuit size, high Q-factor and low insertion loss are the major advantages of this proposed structure compared to the previous approaches