Reconfigurable PA networks using switchable directional couplers as RF switch

Reconfigurable power amplifiers are presented, which utilize switched directional couplers. A power amplifier is built up with several individual smaller stages connected in parallel using the "balanced" amplifier scheme. If the required output power decreases, some of the stages are switched off in order to decrease the DC power consumption and increase the drive of the remaining stages, thus increasing efficiency. The idea is to use switched branch line (right handed and left handed) couplers with switches to ground at their transversal planes as rf power switch in static and dynamic "hot" switching reconfigurable PA networks. The paper presents theoretical considerations and experimental results for built networks.