PCB BASED DOHERTY AMPLIFIER WITH IMPEDANCE MATCHING NETWORK ELEMENTS INTEGRATED IN THE PCB

A Doherty amplifier includes a metal baseplate having a die attach region and a peripheral region, a main amplifier and one or more peaking amplifiers, wherein each amplifier comprises a transistor die that includes at least one RF terminal, a multilayer circuit board and an RF impedance matching network. The multilayer circuit board includes a first side attached to the peripheral region, a second side facing away from the baseplate, a first embedded electrically conductive layer that is separated from the first side by a first embedded composite fiber layer, a second embedded electrically conductive layer that is separated from the second side by a second embedded composite fiber layer, and an embedded dielectric layer that is disposed between the first and second embedded electrically conductive layers, and that has a higher dielectric constant than either of the first and second embedded composite fiber layers. The RF impedance matching network is electrically connected to an RF terminal of at least one of the amplifier transistor dies, and comprises one or more reactive components formed from at least one of the embedded electrically conductive layers.