Dual-Wideband Filtering Phase Shifter With Same Phase Differences, High Frequency Selectivity, and Wide Stopband
Zhuowei Zhang, Gang Zhang, Kam‐Weng Tam, Chi‐Hou Chio, Xin Zhou, Teng Cheng, Ngai Kong
Abstract
In this letter, a novel dual-wideband filtering phase shifter with the same constant phase difference within dual-band and high-frequency selectivity is presented. The proposed filtering phase shifter mainly consists of an asymmetric cross-shaped resonator (ACSR) and a short-ended coupled line. The ACSR includes a pair of parallel coupled line cascading short-ended stubs and open stubs. Meanwhile, by subtly choosing the electric length of the delay line, the same constant phase difference within the dual band can be obtained. For verification, a prototype is designed, fabricated, and measured. Measured results are found to coincide well with the simulated ones, exhibiting dual-wide passbands operating at 2.85 and 4.65 GHz with 3-dB FBW of 40% and 20.5%, respectively, the same in-band phase difference (90° ± 5.6° and 90° ± 4.5°), and sharp frequency selectivity.