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

Abstract

The spatial coverage of a 5G smartphone antenna array is an important factor to consider in the design and implementation of 5G wireless communication systems. In this paper, we present a compact, low-profile, and reconfigurable radiation pattern mm-wave smartphone antenna array that can provide high spatial coverage through its hybrid structure and beam-scanning capabilities. The proposed antenna array introduces PIN diode-controlled strips that enable beam tilting of (±)50° in the vertical direction with respect to a smartphone. In addition, the antenna array can beam scan (±)45° while maintaining a gain of >5 dBi. The compact antenna array measures 28 mm × 5.5 mm × 0.508 mm, including the director and 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: (a) broadside -x, (b) broadside, and (c) 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 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.