Rf transistor output impedance technique for improved efficiency, output power, and bandwidth

Abstract

An RF/microwave circuit is configured to eliminate the physical constraint that requires a sacrifice of one output series inductor wirebond for each shunt inductor wirebond. The circuit employs a multi-level metalized substrate as part of its output impedance matching network. The lower level of the multi-level substrate serves as an intermediate connection point for the output series inductor wirebonds as it extends from the output terminal of an active device to an output metallization pad. The upper level of the multi-level substrate serves to support a DC block capacitor and as an intermediate connection point for the shunt inductor wirebonds. The multi-level substrate allows the series inductor wirebonds to be positioned at a lower height, and the shunt inductor wirebonds at a greater height. Because they are at different heights, the physical constraint of sacrificing a series wirebond per a shunt inductor wirebond can be eliminated. This leads to improved power efficiency, higher gain, and greater bandwidth.