Novel active differential phase splitters in RFIC for wireless applications

Two novel active differential phase splitters have been designed and fabric ated in a GaAs MESFET process. The new circuits employ a concept of feedbac k to adjust gain and phase unbalance separately and accurately. The active phase splitters feature simplicity, low power supply, and wide-band perform ance. The circuits can provide +/-1 dB and 180 +/- 1 degrees differential s ignals within 4-GHz bandwidth, well covering the frequency range currently used for dual-band commercial wireless communications. In narrow-band appli cation, more accurate balanced differential signals can be achieved by exte rnal tuning.