Design of a 0.15–2 GHz high-resolution vector-sum broadband phase shifter with controlled programmable attenuators for stochastic cooling system

• Published in: Review of scientific instruments 2023-12, Vol.94 (12)
• Main Authors: Ma, Liyao, Zhu, Guangyu, Wu, Junxia, Yin, Jia, Wei, Yuan, He, Peilin, Wang, Yongheng, Qiu, Zishuai, Yang, Jiancheng
• Format: Article
• Language: English
• Subjects: Attenuation; Attenuators; Broadband; Cooling systems; Couplers; Insertion loss; Phase error; Phase shift; Phase shifters; Switches
• ISSN: 0034-6748; 1089-7623
• DOI: 10.1063/5.0176593

In this paper, a new 0.15–2 GHz broadband phase shifter with 9-bit phase resolution is presented. This broadband digital adjustable phase shifter is implemented by utilizing the signal vector summation technology. The phase shifter consists of one 90° hybrid coupler, two digital attenuators, two 180° hybrid couplers, two microwave switches, and one combiner. By adjusting the attenuation value of the two digital attenuators, the device creates a minimum 0.7° stepped phase shift. In addition, by switching the two microwave switches, a 360° range of phase shift is achieved while almost keeping the amplitude of the phase shifter constant. The measurement results show that the proposed phase shifter achieves a phase resolution of 0.7° while exhibiting an average insertion loss of 9 ± 2 dB and phase unbalance within ±10°. The calculated RMS phase error of the broadband phase shifter is below 5° from 0.15 to 2 GHz.