Low-Profile P-I-N-Diode-Controlled Bezel Fit Radiation-Pattern Reconfigurable Antenna Arrays for 5G Smartphones

Abstract

The spatial coverage of a fifth-generation (5G) smartphone antenna array is an important factor to consider in the design and implementation of 5G wireless communication systems. In this article, we present a compact, low-profile, and reconfigurable radiation pattern millimeter-wave (mm-wave) smartphone antenna array that can provide high spatial coverage through its hybrid structure and beam-scanning capabilities. The proposed antenna array introduces p-i-n diode-controlled strips that enable beam tilting of (+/-)50 degrees in the vertical direction with respect to a smartphone. In addition, the antenna array can beam scan (+/-)45 degrees while maintaining a gain of >5 dBi. The compact antenna array measures 28 x 5.5 x 0.508 mm, including the director and the reflector, which are situated next to the antenna. The array exhibited a wide -6-dB impedance bandwidth of 3480 MHz (26.42-29.90 GHz) and >25 dB of isolation in the simulation environment. The ON-/OFF-state of the diode results in three operating modes of the antenna array: 1) broadside -x; 2) broadside; and 3) broadside +x modes. The radiation performance of the antenna array was analyzed in each operating mode, with and without a smartphone present. Additionally, power density (PD) analysis was performed for safety analysis using a frequency-dependent homogeneous hand and head model while the antenna array was installed in a smartphone model. Finally, an antenna array was fabricated, and the measurement results were verified, showing good agreement with the simulated results.