Reconfigurable Reflectarray Antenna: A Comparison between Design Using PIN Diodes and Liquid Crystals

Abstract

This work presents the design and analysis of active reflectarray antennas with slot embedded patch element configurations within an X -band frequency range. Two active reflectarray design technologies have been proposed by digital frequency switching using PIN diodes and analogue frequency tuning using liquid crystal-based substrates. A waveguide simulator has been used to perform scattering parameter measurements in order to practically compare the performance of reflectarray designed based on the two active design technologies. PIN diode-based active reflectarray unit cell design is shown to offer a frequency tunability of 0.36 GHz with a dynamic phase range of 226°. On the other hand, liquid crystal-based design provided slightly lower frequency tunability of 0.20 GHz with a dynamic phase range of 124°. Moreover, the higher reflection loss and slow frequency tuning are demonstrated to be the disadvantages of liquid crystal-based designs as compared to PIN diode-based active reflectarray designs.

From Liquid Crystal on Silicon and Liquid Crystal Reflectarray to Reconfigurable Intelligent Surfaces for Post-5G Networks

“…Interestingly, the technological candidates identified here are mostly identical with those used to achieve microwave and millimeter-wave phase shifters [18], except for digital/programmable metamaterials [19] and software-controlled metasurfaces [9,12]. Extensive research and excellent reviews on these candidates have been presented in previous publications on LCbased phase shifters [20] and phased array beam steering [21], which agree with our argument that the "new" concept of RIS could arguably be seen as being driven by LC, more specifically by LC phase shifters based on phased array [22] or LC reflectarray [23,24].…”

Linearly Polarized Millimeter Wave Reflectarray with Mutual Coupling Optimization

“…In its basic form, a reflectarray is a high gain passive antenna, where the phase of individual elements controlled by their geometrical dimensions drives the overall phase performance. While in advanced forms, reflectarrays can be used for beam steering by different methods such as the integration of Radio Frequency Micro Electromechanical Systems (RF MEMS) as switches [11][12][13][14], use of diodes for frequency variations and beam steering [15][16][17][18][19], use of liquid crystals for phase and frequency variation [20][21][22] and mechanical rotation of the antenna for beam steering [23][24][25]. All these techniques have their own advantages and can be used for designing the reflectarray antennas deployable in modern-day applications.…”