An Ultraminiaturized X-Band 6-bit MMIC Phase Shifter Using Capacitance Compensation Technique

作者：Wei Zhao, Yongle Wu, Shuchen Zhen, Weimin Wang · 发表于：IEEE Microwave and Wireless Technology Letters · 年份：2025 · DOI：10.1109/lmwt.2025.3631501 · 被引用次数：2 · 研究领域：Radio Frequency Integrated Circuit Design、Advanced Power Amplifier Design、Microwave Engineering and Waveguides

In this letter, a capacitance compensation technique (CCT) is proposed to simultaneously reduce the area and improve the in-band performance of switch-type phase shifters (STPSs). For the modified inductive T-type phase-shifting unit (MITPSU) using the CCT, the compensating capacitors introduce additional degrees of freedom, which enable the use of minimal-size high electron mobility transistor (HEMT) switches and spiral inductors. Moreover, the resonance of the MITPSU can be tuned to a desired frequency, thereby enhancing the in-band matching level and minimizing the insertion loss (IL) and phase variations. To verify the concept, an X-band 6-bit on-chip STPS using a 0.25-$\mu $m GaAs pHEMT process is designed and fabricated. The core area is only$1.25~{\text {mm}^{2}}$. The measured average IL is from 6.6 to 7.9dB, and the return loss (RL) is better than 10 dB. The rms phase and IL errors are better than 4.1 ° and 0.45 dB. The measured IP${}_{\text {1 dB}}$is 30.1 dBm at 10 GHz.