Abstract: A circuit for matching the impedance of an output load to an active device includes a transformer including a first winding having a terminal for coupling to the output of the active device and a second winding electromagnetically coupled to the first winding, and a plurality of taps, each of the plurality of taps having a first end coupled to a position on the second winding corresponding to a ratio of the second winding to first winding differing from other ones of the plurality of taps, and a second end. The matching circuit further includes a plurality of MEMS switches each having a control input for receiving a corresponding control signal, a first terminal coupled to the second end of a corresponding one of the plurality of taps, and a switched output selectively coupled to a matching junction in response to the corresponding control signal.

Abstract: A circuit for matching the impedance of an output load to an active device includes a transformer including a first winding having a terminal for coupling to the output of the active device and a second winding electromagnetically coupled to the first winding, and a plurality of taps, each of the plurality of taps having a first end coupled to a position on the second winding corresponding to a ratio of the second winding to first winding differing from other ones of the plurality of taps, and a second end. The matching circuit further includes a plurality of MEMS switches each having a control input for receiving a corresponding control signal, a first terminal coupled to the second end of a corresponding one of the plurality of taps, and a switched output selectively coupled to a matching junction in response to the corresponding control signal.

Abstract: The collectors or the bases of three RF power transistors, each mounted on a separate substrate, are connected in parallel by means of transmission line segments connected so that the current flowing in the center transistor splits evenly and joins the current from the end transistors at an initial combining point, which points are then connected to a final combining point to provide the shortest transmission lines to the initial and final combining points.