The Orthogonal LMBA: A Novel RFPA Architecture With Broadband Reconfigurability

A novel RF power amplifier (RFPA) architecture, the orthogonal load-modulated balanced amplifier, or OLMBA, is described and demonstrated. Compared to the load-modulated balanced amplifier (LMBA), the OLMBA displays many of the same benefits, such as active adaptive tuning using the phase and amplitude of an external control signal, but with much lower power requirements on the control signal power (CSP). As such, a useful range of active tuning can be implemented with essentially no impact on overall efficiency due to the low level of a control signal. A demonstrator is described and measured, which delivers 30 W at a minimum of 50% efficiency over a 0.65-3.25-GHz bandwidth.