A Broadband Array Antenna Based on E-Shaped Folded Strip Elements for Millimeter-Wave N259/N260 Applications

A low-profile, wideband linearly-polarization array antenna based on broadband E-shaped folded strip elements is proposed. The antenna unit consists of a 2×2 array of E-shaped folded strip elements and four metalized through-holes. The microstrip line, located on the underside of an extremely thin dielectric substrate, utilizes a cross-shaped slot for its coupled feeding mechanism. This configuration markedly enhances the compatibility with circuits at millimeter-wave frequencies and also offers the advantage of a low-profile design. The simulated performance of the antenna module shows an impedance bandwidth covering 71%, extending from 21.43 GHz to 45 GHz, along with a peak gain of 5.925 dBi. Moreover, it maintains a cross-polarization discrimination level that is greater than 25 dB. To demonstrate the wideband and high-gain characteristics, a 2 × 2 array of linearly polarized antennas has been crafted, featuring a straightforward microstrip feed system and eliminating the necessity for an extra enclosure made of dielectric material. The simulated data reveal commendable characteristics regarding impedance correlation, gain, and the patterns of radiation, rendering the array well-suited for deployment in millimeter-wave applications designated as N259 and N260.