Differentially Fed, 1-D Phased-Array Antenna-on-Display Featuring Wideband and Polarization Agility for Millimeter-Wave Wireless Applications

This article presents a 1-D differentially fed antenna-on-display (AoD) structure capable of providing a wideband and polarization reconfigurable radiation pattern. The antenna element topology consists of a rounded truncated main radiator connected to a differential feedline, and two parasitic structures are incorporated to enhance the impedance bandwidth. The operating principle of the proposed antenna element structure is analyzed comprehensively, including the input impedance, surface current distribution, and vector electric-field distribution. By adjusting the phase of the current applied to the differential feedline, the differentially fed AoD achieves polarization agility. The two phased-array antenna models are designed, fabricated, and verified. The first model incorporates a passive 1:4 power divider with a fixed phased delay line to characterize the realized gain and radiation properties. The measured and simulated radiation patterns exhibit a maximum gain of 9.45/9.50 dBi at 28 GHz and 8.99/8.14 dBi at 39 GHz, demonstrating good correlation while maintaining a cross-polarization level of over 20 dB. The second model integrates the 5G mmWave RF front-end module with the display-integrated differentially fed AoD. The fabricated model is capable of beam steering from −35° to 35° at 28 GHz.