Dual-Band Differential Phase Shifter Using Phase- Slope Alignment on Coupled Resonators

• Published in: IEEE microwave and wireless components letters 2018-12, Vol.28 (12), p.1092-1094
• Main Authors: Lyu, Yun-Peng, Zhu, Lei, Cheng, Chong-Hu
• Format: Article
• Language: English
• Subjects: Alignment; Constant phase shift; coupled resonators; differential phase shifter; Dual band; dual-band operation; Impedance; Phase shifters; phase-slope alignment; Resonators
• ISSN: 1531-1309; 2771-957X; 1558-1764; 2771-9588
• DOI: 10.1109/LMWC.2018.2875997

In this letter, we propose a new class of phase shifter which can provide different constant phase shifts at two bands for the first time. The prescribed phase shifts \Delta \Phi _{\mathbf {1}}({f}_{\mathbf {1}}) and \Delta \Phi _{\mathbf {2}}({f}_{\mathbf {2}}) and frequency ratio ( {n} ={f}_{\mathbf {2}}/{f}_{\mathbf {1}} ) of the two bands can be obtained by the developed dual-band phase-shifting line on C-section. Meanwhile, the dual-band phase-slope alignment is first realized by virtue of the two groups of coupled resonators, resulting to independently control the phase slopes at two separated bands as required. The closed-form equations and design charts are further given. For verification, a prototype dual-band phase shifter operating at 3.0 and 5.4 GHz ( n = 1.8 ) is designed, fabricated, and tested. The measured results show the proposed phase shifter exactly achieves prescribed constant phase shifts of 90° ± 2.3° over 2.76-3.31 GHz (18%) and 180° ± 2.7° over 4.97-5.80 GHz (15%). Both the simulation and measured results are recorded with good agreement.