Patent ID: 6819200
Filing Date: 2004-11-16
Classification: H03H

Abstract:
A balun and impedance transformer for a power amplifier, comprising:a first 4:1 impedance transformer having a differential input port and a differential output port the differential input port coupled to the power amplifier; a balun configured in a Marchand configuration, the balun having a differential input port with a coupling capacitor coupled therebetween and the balun having a single-ended output port, the balun's differential input port coupled to the differential output port of the first 4:1 impedance transformer; a second 4:1 impedances transformer having a single-ended input port capacitively coupled to the balun's single-ended output port, the second 4:1 impedance transformer having a single-ended output port; and the first 4:1 impedance transformer, the balun and the second 4:1 impedance transformer are implemented using Low Temperature Cofired Ceramics (LTCC) technology, wherein the first 4:1 impedance transformer and the balun provide DC bias to the power amplifier and further comprising a decoupling capacitor on the DC bias to serve as a floating ground place.