Multi-Layers High Directivity Couplers

摘要

Abstract - The presented high directivity narrowband multi-layer couplers consist of two transmission lines located on different layers of PCB board and coupled through spatially small coupling structures. The main lines are coupled only at two points. The coupling value can be set from 3 dB to 30 dB. The couplers can be realized in different multilayer stack-ups thus can be easily integrated into variety of PCB circuits. The directivity of the couplers is better than 30 dB in the narrow relative bandwidth of 2 %. The matching is better than 25 dB.