Design and Analysis of an Electronically Continuous Tunable Phase Shifter for Phased Array Antennas

抄録

In this article, the authors propose an electronic, linear, continuously tunable phase shifter (PS) with an adjustable phase range of leading +180° to delay -180° within the phase shift bandwidth (PSBW) and a maximum adjustable phase range of +240° to -240° within the half power bandwidth (HPBW). This PS enables flexible design of its operating frequency and PSBW and maintaining a constant linear slope of -116.6° per susceptance (jb) for any design PSBW. The PS consists of two different wavelengths of transmission lines and four identical LC parallel resonators (LC tanks), with phase variation achieved by adjusting the capacitance values, susceptance values, or resonance frequencies within the LC tanks. The authors also present an analysis of the electrical theory underlying this PS. Theoretically, the transmission coefficient T ranges from 0dB to -0.973dB, and the reflection coefficient Γ peaks at -6.99dB. Additionally, the authors provide design guidelines for the PS. Based on these guidelines and available lumped components, a PS operating at 3GHz with a PSBW of 400MHz was developed. Finally, measurement results confirm a generally consistent between theoretical predictions and practical implementation. This demonstrates that the proposed PS can be designed with arbitrary center frequencies and PSBW, exhibiting excellent S-parameters and linear continuously tunable phase shifting performance.