A Cavity-Backed Circular SIW Antenna for X-band Applications

A cavity-backed circular substrate integrated waveguide (SIW) antenna is presented in this paper. The proposed antenna is designed to radiate at 10 GHz. It has high power handling capacity along with unidirectional high broadside peak gain of 7.3 dBi due to its cavity-backed structure. By varying the radius of the annular slot, the antenna can be operated throughout the X-band and hence, frequency tunability is achieved with its simple structure. The antenna exhibits a fractional bandwidth (FBW) of 4.1% at its resonant frequency and a front-toback ratio of 15 dB. The proposed antenna is a suitable candidate for X-band high gain unidirectional narrowband applications.