Realization of a Compact and High-Performance Power Divider Using Parallel RC Isolation Network

Abstract

In this brief, the design methodology of high- performance lumped-distributed Wilkinson power divider with extremely small chip area is proposed. A parallel capacitor is included at the input port (port 1) to compensate the imaginary part of the input admittance for input matching. A parallel RC network is connected between the output ports (ports 2 and 3) to attain perfect input matching and isolation of the output ports in the odd- and the even-mode excitations. Dual spiral structure with transmission line length of about λ/10 and symmetrical layout is adopted to achieve miniature area and small amplitude imbalance (AI) and phase difference (PD). At 33 GHz, the prototyped power divider achieves S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> of -17.8 dB, S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">22</sub> and S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">33</sub> of -22.7 dB, S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">32</sub> of -34.7 dB, S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">21</sub> of -4.1 dB, and S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">31</sub> of -4.07 dB. The corresponding AI is -0.03 dB and PD is -0.08°. The chip area is only 1.2×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-4</sup> λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , one of the smallest normalized chip area ever reported for millimeter-wave (mm-wave) power dividers. The superb results of the power divider indicate that it is suitable for power division/combination in mm-wave transceivers.