C/K-Band Dual-Frequency Shared-Aperture Antenna with High Isolation

In this paper, we propose a dual-frequency shared-aperture antenna operating at 4.7/25.2 GHz. By embedding a high-frequency dielectric resonant antenna (DRA) into a perforated discrete patch of a low-frequency patch antenna, the two antennas are highly integrated. The proposed antenna has a compact size of 0.51λ<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> × 0.51λ<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> × 0.05λ<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> (λ<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> is the wavelength in the vacuum at 4.7 GHz). Simulation results show that the -10 dB impedance bandwidths of this shared-aperture antenna are 4.26-5.15 GHz (18.9%) and 23.7-26.7 GHz (11.9%), with peak gains within the bands of 6.2 dBi and 16.6 dBi, respectively. The channel isolation between the two bands is more than 40 dB at low frequency and 20 dB at high frequency.