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Xi FU Yun WANG Xiaolin WANG Xiaofan GU Xueting LUO Zheng LI Jian PANG Atsushi SHIRANE Kenichi OKADA
This paper presents a high-resolution and low-insertion-loss CMOS hybrid phase shifter with a nonuniform matching technique for satellite communication (SATCOM). The proposed hybrid phase shifter includes three 45° coarse phase-shifting stages and one 45° fine phase-tuning stage. The coarse stages are realized by bridged-T switch-type phase shifters (STPS) with 45° phase steps. The fine-tuning stage is based on a reflective-type phase shifter (RTPS) with two identical LC load tanks for phase tuning. A 0.8° phase resolution is realized by this work to support fine beam steering for the SATCOM. To further reduce the chain insertion loss, a nonuniform matching technique is utilized at the coarse stages. For the coarse and fine stages, the measured RMS gain errors at 29GHz are 0.7dB and 0.3dB, respectively. The measured RMS phase errors are 0.8° and 0.4°, respectively. The proposed hybrid phase shifter maintains return losses of all phase states less than -12dB from 24GHz to 34GHz. The presented hybrid phase shifter is fabricated in a standard 65-nm CMOS technology with a 0.14mm2 active area.
Chai Eu GUAN Ahmed I.A. GALAL Nagamitsu MIZOGUCHI Akira ISHIKAWA Shugo FUKAGAWA Ryuji KITAYA Haruichi KANAYA
The analysis and design of a full 360 degrees hybrid coupler phase shifter with integrated distributed elements low pass filters is presented. Pi-section filter is incorporated into hybrid coupler phase shifter for harmonic suppression. The physical size of the proposed structure is close to that of the conventional hybrid coupler phase shifter. The maximum phase shift range is bounded by the port impedance ratio of the hybrid coupler phase shifter. Furthermore, the phase shift range is reduced if series inductance in the reflective load deviates from the optimum value. Numerical and parametric analyses are used to find the equivalent circuit of the pi-section filter for consistent relative phase shift. To validate our analysis, the proposed phase shifter operates at 8.6GHz was fabricated and measured. Over the frequency range of interest, the fabricated phase shifter suppresses second harmonic and achieves analog phase shift of 0 to 360 degrees at the passband, agreeing with the theoretical and simulation results.