This study develops a compact balun layout to minimize amplitude imbalance. Three baluns with different metal layers are fabricated using 0.13-??m CMOS technology and their imbalance performance evaluated. Measurement made using eight metal layers in coil windings at a particular layout reveal that the proposed device exhibits minimal amplitude and phase imbalance of 0.2 dB and ??0.5?? with a chip outer dimension of 100 ??m .