Balanced Duplex Filtering Dielectric Resonator Antenna with High Isolation Performance

A balanced duplex filtering dielectric resonator antenna (DF-DRA) is proposed in this paper. This proposed DF-DRA combines the functions of the antenna, the filter and the duplexer into one highly integrated multifunctional module. The designed dual-mode rectangular DRA operating as a common radiation structure is excited by two cross slots etched on the top of a dual-mode substrate integrated waveguide (SIW) cavity. The dual-mode SIW cavity is fabricated and worked as a common filtering element. Then, the SIW cavity is fed by two pairs of differential input/out ports on the bottom layer, which not only suppresses the unwanted common mode (CM) noise but significantly improves the isolation between the lower and higher channel. The synthesis co-design methodology is utilized to process the integration design. Measured results show that the balanced DF-DRA can operate with differential mode (DM) 10dB impedance bandwidth of 2.5% (5.15-5.28 GHz) and 3.4% (5.69-5.89 GHz) for two channels, respectively. The measured DM peak realized gains are 5.18-5.91 dBi and 5.11-6.57 dBi at two channels. The DM channel isolation is up to 60dB.