Liquid Crystal Based Tunable Reflection-Type Power Divider

Tunable power dividers are a key-component for adaptive arrays employing full beam synthesis. Here, the concept of a tunable reflection-type power divider is presented, which utilizes the edge slope of a tunable filter. In this work, the filter's transmission and reflection are separated by a hybrid coupler circuit. Design equations are derived on basis of a Butterworth prototype function and a proof-of-concept demonstrator is realized for 12 GHz. The tunable filter is implemented by liquid crystal. The measurement proofs the functionality of the presented concept, achieving a dynamic range of 9 dB for both output branches. To the authors' best knowledge, this is the first time, such a concept is presented.