1-Bit Reconfigurable Beam Steering Planar Array Antenna Based on Reflectarray Feeding

Abstract

In this paper, we present a method for reducing the quantization lobe in a 1-bit beam steering planar array antenna. The method is inspired by reflectarray feeding in such a way that as we move away from the center of the array, the phase becomes more negative. This type of element phasing disturbs the periodicity of the quantization phase error and therefore suppresses the quantization lobe. Each 1-bit antenna element has two phase states (0 and 180°) that are provided through two symmetrical feeding points and are controlled with two PIN diodes. The planar array is fed by a series microstrip line network. One prototype of the proposed planar array with $8\times 8$ elements was fabricated and tested at 3.4 GHz, which showed a measured scan range between −45° and +45° with a maximum quantization lobe level of −9 dB and a gain variation of 1.5 dB. The proposed 1-bit beam scanning antenna has a much simpler feeding network than other planar array antennas. The overall thickness of the proposed array antenna is only $0.045\lambda _{\text {o}}$ , which has a much lower profile than 1-bit reconfigurable reflectarray and transmitarray antennas with the same specifications. This proposed antenna is a usable and suitable candidate for wireless communication applications.

Keywords

• 1-Bit quantization lobe
• reconfigurable antenna
• planar array
• microstrip antenna
• beam steering