High-Isolation Dual-Polarized Leaky-Wave Antenna With Fixed Beam for Full-Duplex Millimeter-Wave Applications

In this article, a high-isolation dual-polarized leaky-wave antenna (LWA) with a fixed beam is proposed for full-duplex millimeter-wave (mm-wave) applications. The proposed antenna consists of a dual-polarized LWA array and an orthogonally differential feeding network. The proposed dual-polarized LWA array is developed based on the proposed LWA unit cell, which is suitable for differential feed, and the open stopband is eliminated. The proposed feeding network provides two pairs of orthogonally differential excitation for the LWA array to realize the fixed beam with orthogonal polarization in boresight direction; the high interport isolation is implemented as well. The prototype for demonstration purposes is fabricated and measured. The measured results show that the proposed antenna exhibits an operating band from 27.6 to 29.5 GHz with a maximum gain of up to 24 dBi. Furthermore, the measured interport isolation is higher than 51 dB within the operating band, where the maximum isolation is up to 60 dB. The measured cross-polarization levels are also very low, less than −27 dB. The proposed antenna features high gain, high interport isolation, and good co-/cross-polarization isolation, achieving a good Tx/Rx separation for the in-band full-duplex applications at mm-wave frequencies.