Wideband printed log-periodic balun

A compact printed log-periodic balance to unbalance (balun) transformer capable of operating over an octave band is presented for tunable antennas used for calibration measurements (ANSI C63.5). The balun can achieve more than octave bandwidth (0.8 GHz to 2.4 GHz) impedance match (VSWR < 2) with a magnitude balance at the output ports of /spl plusmn/ 0.5 dB and a phase balance of 180/spl deg/ /spl plusmn/ 5/spl deg/. Advanced microwave design systems package is used to optimize the balun performance over the wideband and the simulated results are compared with measured results.