Coupled Line Unit Cell for Independent Control of Even and Odd Mode Phase Delays

摘要

Coupled lines are essential to numerous microwave components such as directional couplers, filters, and phase shifters. In this paper, we propose a topology for a tunable coupled line unit cell. In the design, the even and odd mode phase delays can be tuned independently of one another while maintaining an impedance match for both modes. An analytical description of the coupled line unit cell is presented in addition to experimental results for a fabricated structure designed to operate in the X-band. Such a unit cell could be used to simultaneously control the coupling coefficient and transmission phase of a directional coupler in real time.