E -Band Low-Profile, Wideband 45° Linearly Polarized Slot-Loaded Patch and Its Array for Millimeter-Wave Communications

A series of E-band low-profile wideband antenna arrays with 45° and ±45° dual linear polarizations is presented for high-speed millimeter-wave communication applications. The array element consists of a corner-fed patch with a tilted slot cut at its edge, which suppresses unwanted modes in order to generate the desired 45° linear polarization. Comparing to a traditional 45° tilted patch, the proposed element gets rid of the bending feedline and realizes a higher isolation level between adjacent patches in the side-by-side arrangement. For proof-of-concept demonstration, a $2 \times 8$ array with 45° linear polarization was fabricated and measured, exhibiting a good agreement between simulation and measured results. The proposed array prototype possesses a -10 dB impedance bandwidth of 10.6% (74.3-82.5 GHz). Moreover, a dual $1 \times 8$ array with ±45° dual polarization is also presented, showing a bandwidth of 9.7% (74.4-81.9 GHz) and a high isolation level of greater than 25 dB. The proposed E-band planar arrays own the advantages of low profile, i.e., $\sim 0.067\lambda _{0}$ , single layer, low fabrication cost, simple structure, wide operational bandwidth, i.e., ~10%, and polarization flexibility. They represent promising candidates for high-speed E-band communications.