Compact and Wideband Cavity-Backed Antenna With Elliptical Coupling Slot and Elliptical Aperture for Satellite Communications Transceiver Applications

Abstract

A wideband full-metal cavity-backed antenna with elliptical coupling slot and elliptical aperture is proposed. The antenna consists of two elliptical structures a coupling slot and a radiating aperture which are placed on the feed waveguide side and the load side of a rectangular metal cavity resonator respectively. By using an elliptical slot/aperture the impedance bandwidth and gain of the antenna are found to be considerably improved in the same footprint and without increasing complexity compared to rectangular slot/aperture and also circular aperture. A prototype of the proposed wideband antenna is fabricated by using the additive manufacturing techniques of 3D printing with polylactic acid (PLA) material which is covered with aluminum tape to validate the design at Ku-band for satellite communication (SatCom). The measured results show that the antenna has an impedance bandwidth of 4 GHz (10.86-14.86 GHz for |S-11| < -15 dB) which gives a fractional bandwidth (FBW) of 31.1%. With low cross-polarization being less than -25 dB at broadside the antenna has a peak gain of 9 dBi. The proposed antenna is also compact with a total volume of about 1.1 lambda(3 )(0)at the center frequency.