A Six-Port Receiver's Analog Front-End of Reduced Size Based on a Multi-Layer Layout

In this paper a compact front-end of a six-port receiver is presented based on a multi-layer circuit topology. For higher frequencies the six-port receiver architecture offers a good alternative to common receiver concepts. One drawback is the occupied size of the microwave couplers used in the analog front-end depending normally directly on the wave length and is opposed to an implementation of the passive six-port structure on a MMIC. With the results of the investigations presented in this paper a reduction in size of the six-port's transmission line structure of about 79% is achievable. The performance of the proposed multi-layer structure is compared to the common planar topology and shows only slight degradation.