Abstract: The linearity of a wideband RF power transistor amplifier is improved by including output matching circuit and an integrated bias/RF diplexer with RF and video bypassing capacitor network within the transistor package and connected directly to the transistor. By placing the RF and video bypass power supply circuitry within the package and close to the transistor, the input impedance resonance can be increased from approximately 50 MHz to over 125 MHz, thereby reducing AM/PM distortion in the output signal.

Abstract: A coplanar coupler for use with microstrip input and output ports includes a printed circuit substrate in which first and second metal input ports are formed on a top surface and cooperate with a metal layer on the bottom surface as microstrip lines, and first and second metal output ports formed on the top surface which cooperate with the metal layer on the bottom surface as microstrip lines. The metal layer on the bottom surface functions as a ground plane for the input ports and the output ports, the metal layer being removed in a coupler region underlying at least portions of the metal input and output ports and extending therebetween. First and second metal lines are formed on the bottom surface in the coupler region and function as a coplanar coupler for the input and output ports. Electrical vias in the substrate interconnect the ports and the coplanar coupler.