The Design of Programmable Transmitarray with Independent Controls of Transmission Amplitude and Phase

TL;DR

This paper presents a novel programmable transmitarray design in the C-band that independently controls transmission amplitude and phase, enabling advanced electromagnetic manipulation for beamforming applications.

Contribution

The paper introduces a new transmitarray unit cell with cascaded structures allowing independent amplitude and phase control, validated through fabrication and experiments.

Findings

Transmission magnitude ranges from -16 dB to -3.6 dB

Phase coverage of 270 degrees with 16-bit control

Successful implementation of adaptive beamforming

Abstract

A design method of programmable transmitarray with independent controls of transmission amplitude and phase is proposed in C-band. The unit cell with cascaded structures mainly consists of four parts, including the receiving antenna, reconfigurable attenuator with PIN diodes, reconfigurable phase shifter with varactors and transmitting antenna. Correspondingly, various manipulations of spatial electromagnetic (EM) fields are achieved by varying the bias voltages of PIN diodes and varactors in the transmitarray. The fabricated unit cell is measured in a standard waveguide, and the whole array with 8*8 unit cells is measured with two horns for calibration of the programmable EM features. The experimental results show that the transmission magnitude can range from -16 dB to -3.6 dB and the transmission phase achieves 270-degree coverage independently under the 16-bit programmable control. To further exhibit the capability and functionality of the proposed transmitarray, the waveform engineering of adaptive beamforming and power-allocation beamforming are separately realized in the experiment. The measured results have good agreements with our theoretical calculations, verifying the validity of our design method.