New switchable directional couplers for recon figurable RF-networks

This paper presents new types of switchable directional couplers. Two different types of branch-line couplers (Termed type A and type B) are described, equipped with switches to ground on there branches, which allow to switch between the normal coupling operation and a bypass state. A relative bandwidth of approximately 5% is achieved. Much wider relative bandwidth up to 50% is obtained with a switchable Lange coupler. All described couplers are impedance matched in both switching states. The paper presents the construction of the circuits, simulations and the experimental realization at ~2 GHz.