A Single Patch Antenna With Broadside and Conical Radiation Patterns for 3G/4G Pattern Diversity
A single square patch antenna for pattern diversity is investigated. The proposed antenna consists of a double feed square patch antenna with a rat race network. By switching the feeding ports, the different radiation patterns for two modes TM10 mode and the capacitive loaded monopole radiating mode) operating over an overlapped frequency band from 1.88 to 2.34 GHz are achieved. TM10 mode reveals good broadside radiation patterns, and the capacitive loaded monopole radiating mode shows conical radiation patterns. The antenna is fabricated and tested. The measured gains across the common frequency band are 8.9 9.9 and 2.8 3.8 dBi for TM10 mode and the capacitive loaded monopole radiating mode, respectively. Moreover, the measured bandwidths of 10 dB reflection coefficient are 750 MHz (1.59 2.34 GHz, 38.2% for TM10 mode and 880 MHz (1.88 2.76 GHz, 37.9% for the capacitive loaded monopole radiating mode. High isolation 20 dB between the two feeding ports for the common impedance matching band is achieved. These results make the single dual port patch antenna an attractive solution for 3G/4G pattern diversity applications such as in gym scenarios.
IEEE Antennas and Wireless Propagation Letters