A monolithically integrable spiral balun (20) comprises a first transmission line (26) forming a spiral that winds in a first direction and has a first end coupled to receive an input signal. A second transmission line forms a second spiral that winds in a second direction and has a first end and has a second end electrically coupled to the second end of the first transmission line. The third transmission line (22) forms a third spiral that interleaves the first spiral and winds in the second direction and has a first end for providing a first output and a second end for coupling to a first potential. A fourth transmission line (44) forms a fourth spiral that interleaves the second transmission line and winds in the first direction and has a first end for providing a second output and a second end for coupling to a second potential.
