Application of PBG microstrip circuits for enhancing the performance of high-density substrate patch antennas

We present EM simulation results of a high-density substrate patch antenna integrated with a microstrip photonic bandgap (PBG) circuit. It is demonstrated that application of such it circuit in an active integrated antenna eliminates undesired high-order frequency harmonics and patch radiation modes, and improves the return-loss level at the fundamental-mode frequency of the patch. Optimization of the PBG periodic element geometry provides harmonics filtering in a wide frequency band. The surface current density on the microstrip PBG circuit integrated antenna has been calculated in illustrating the mechanism of the high-order radiation harmonics timing. It is noted that making rise of a high-density dielectric substrate allows easy integration of antenna elements and MMIC circuitry for novel active integrated transmitter front ends. (C) 2002 John Wiley Sons, Inc.