A COMPACT DUAL-BAND MONOPOLAR PATCH ANTENNA USING TM01 AND TM41 MODES

Abstract

A compact dual-band monopolar patch antenna (DBMPA) using the TM01 and TM41 modes is proposed. The DBMPA consists of: (1) coupled-fed fan-shaped patches with four shorting pins each to generate the TM41 higher order resonant mode for monopole-like radiation pattern with compact size, and (2) a cross-shaped co-planar coupled feed patch at the center for impedance matching and exciting the TM01 mode. The proposed antenna operates in the industrial, scientific, and medical (ISM) 2.45 GHz band and the ISM 5.8 GHz band, with monopole-like radiation characteristic in both bands. The proposed DBMPA only has a thickness of 0.01 lambda(0) and a diameter of 0.39 (0). The corresponding fractional 10-dB return loss bandwidths and maximum gains are 3.4% and -0.05 dBi for the ISM 2.45 GHz band, and 3.8% and 2.45 dBi for the ISM 5.8 GHz band.