Ultracompact Quarter-Mode Substrate Integrated Waveguide Self-Diplexing Antenna

A highly compact substrate integrated waveguide (SIW) self-diplexing antenna, operating at wireless local area network bands (3.6 and 5.4 GHz), is proposed in this letter. The antenna consists of two closely placed (0.022? g , where ? the guided wavelength 3.6 GHz) quarter-mode SIW resonators, exited by coaxial probes. Two rectangular slots are added to closed-ends each resonator generate additional capacitances. Therefore, both resonators operate below their fundamental frequencies, hence, miniaturization achieved. Moreover, a reliable circuit model developed validate design process. has ultracompact dimensions 0.08? 2 with simulated gains 4.9 5.34 dBi GHz, respectively. In addition, isolation levels 32.5 36.6 dB lower higher resonant bands, Furthermore, frequencies can be independently controlled changing length capacitive slots. Due its compactness, independent resonance control high isolation, suitable for planar radio frequency components.