Wideband SIW Based Self-diplexing Antenna Using Parasitic Slots

A wideband self-diplexing antenna (SDAN) based on a substrate integrated waveguide (SIWG) is investigated and presented for satellite communications in X-band. TE120 mode is utilized for self-diplexing operation. For exciting dual frequencies, the SIWG cavity structure is divided into two sub-cavities by utilizing an additional array of metallic vias in the middle of the cavity. Three rectangular slots (one main slot and two parasitic slots) are stacked together and loaded on each SIWG sub-cavity for achieving wide bandwidth. The antenna exhibits a relative impedance bandwidth of 8.1% and 9.1% at 8.7GHz and 10.5GHz, respectively. Strong self-diplexing characteristics are achieved with a minimum 20dB isolation across the entire bandwidth. The broadside radiation characteristics are achieved with low level of cross polarization. The peak realized gain at aforementioned two working frequencies is 5.11dBi and 7dBi. The excellent performance of suggested SDAN makes it a strong choice for multiple frequency transmit and receive operation in X-band.