Frequency Agile Microstrip Patch Antenna Using an Anisotropic Artificial Dielectric Layer (AADL): Modeling and Design

Abstract

This paper presents the modeling and design of a frequency agile antenna using an anisotropic artificial dielectric layer (AADL) for multi-band phased array radar applications. The proposed AADL material is placed underneath the patch radiator and is designed using periodically arranged metallic cylinders in which varying height, diameter, and the distance used between them allows the control of the effective permittivity of the patch antenna. Closed form design expressions are formulated to synthesize the dielectric properties of the AADL as a function of the cylindrical unit cell dimensions. Design trade-offs based on the proposed formulation and numerical simulations show the overall performance of the AADL on microstrip patch (MS) antennas. To validate the proposed concept, five individual AADL MS patch antennas in C-band were designed, fabricated, and tested. Simulated and measured results (s-parameters and radiation patterns) are in good agreement with the results obtained from the theoretical model. The proposed AADL concept has the potential to be used in the development of future reconfigurable tunable multiband antennas that use liquid metal to dynamically change the heights of the cylinders.

Keywords

• Anisotropic
• artificial dielectric layer
• low-profile antenna
• microstrip patch antenna
• multi-band antenna
• reconfigurable