An Easy-to-Embed Reflective-Type Phase Shifter Utilizing Two-Step Phase Extraction Process

In this paper, a low-cost and easy-to-embed reflective-type phase shifter (RTPS) designed by the two-step phase extraction process is proposed. The RTPS consists of a 3dB branch-line coupler and two tunable parallel L-C loads. The innovation of this paper lies in the proposed two-step phase extraction process, which reduces the number of RTPS states significantly during the design and testing. The designed RTPS exhibits a phase shift range of over 360° and a low insertion loss. Furthermore, by adjusting the inductance of the loads, the phase step of RTPS can be optimized. In addition, the proposed RTPS is designed with stripline, making it suitable for integration into multi-layer circuits. For performance evaluation, a prototype of 7-bit 360° RTPS is manufactured. The RTPS operates from 2.4 GHz to 2.5 GHz, with a phase shift range of 386.8° at 2.45 GHz and a measured insertion loss of $2.21 \pm 0.82 \mathrm{~dB}$.