Hexa-band SIW cavity antenna system integrating two antennas with high isolation

Abstract

A hexa-band substrate integrated waveguide (SIW) cavity antenna system integrating two antennas with high isolation is proposed. A square SIW cavity is divided by a wide slot into two half sub-cavities. Two narrow slots are etched in the upper sub-cavity and other two slots are cut in the lower sub-cavity to achieve multi-band operation. Six half-mode resonances with different sizes can occur in a single cavity. They are excited by two coaxial ports to form two integrated antennas. A fabricated sample with the overall size of 0.63λ0 × 0.63λ0 has been measured. The measured frequencies excited by port 1 are 2.31 GHz (f1), 2.91 GHz (f2), and 3.35 GHz (f3). The resonating frequencies excited by port 2 are 2.57 GHz (f4), 3.11 GHz (f5), and 3.61 GHz (f6). The measured gain and efficiency at the above frequencies are higher than 5 dBi and 72%, respectively. Moreover, the measured isolation between these integrated antennas is better than 22 dB within the frequency of interest. The proposed antenna system offers advantages of compact size, hexa-band operation, high isolation, and unidirectional radiation, which has potential applications in multi-standard wireless systems.