Dielectric resonator used as radome and antenna: A new concept for large frequency ratio shared aperture antenna design

This paper presents a novel transmissive type L/Ku dual-band dual-polarization (DBDP) shared aperture antenna (SAA) with a large frequency ratio. The L-band antenna employs a balanced-fed hollow dielectric resonator antenna (DRA), which has broadband and low cross-polarization; also, it can be used as a radome to protect the Ku-band array. The Ku-band uses a 4 x 4 dual-polarized microstrip antenna array placed inside the hollow DRA and radiates through it. In order to verify the design, a prototype antenna was manufactured and measured. The measured result shows that the SAA covering the frequency bands of 0.95-1.42 GHz and 13.16-13.84 GHz with the reflection coefficient below -10 dB, the isolation between polarizations is better than 40 dB for L-band and 25 dB for Ku-band, the measured gain is 4.8 dBi for L-band and 16.7 dBi for Ku-band, and the cross-polarization level for L- and Ku-band is lower than -28 and -20 dB, respectively.