US Patent 8633781 Combined balun and impedance matching circuit

An apparatus for providing impedance matching between a single-ended circuit and a differential circuit includes first and second capacitors and first and second inductors. The first capacitor is connected between an input/output of the single-ended circuit and a first differential input/output of the differential circuit. The first inductor is connected between the input/output of the single-ended circuit and a second differential input/output of the differential circuit. The second capacitor is connected between the second differential input/output of the differential circuit and ground. The second inductor is connected between the first differential input/output of the differential circuit and the second differential input/output of the differential circuit.