A Wideband SIW-Based Slot Antenna for D-Band Applications

In this letter, a wideband substrate integrated waveguide (SIW) based slot antenna is designed for D-band applications. A wideband response is attributed to the merging of closely lying six resonance frequencies. Two of them at frequencies of 114.25 GHz and 134.75 GHz signifies the excitation of TE310 and TE120 modes, respectively. Themodes at 124 GHz and 144 GHz are identified as hybridmodes that are formed fromthe combination of TE310-TE120 and TE120-TE220 modes, respectively. The upper two resonances at the frequencies of 154 GHz and 160 GHz occur due to TE220-TE320 based hybrid modes. A two-step wideband WR6-SIW transition is also designed and integrated with the antenna for measurement purpose. In the first step, the three-section Chebyshev transition is developed to match the impedance of standard WR6 with a rectangularwaveguide (RWG) of the same height as that of the PCB. In the second step, the RWG is matched with SIW using a dielectric extension. The final antenna with transition is simulated and measured. A wide -10 dB impedance bandwidth for vertical bar S-11 vertical bar = -10 dB of 42.86% (110-170 GHz) is obtained. The gain and radiation measurements were also performed after constructing an in-house measurement system.