Publication Date

Fall 2011

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Electrical Engineering

Advisor

Sotoudeh Hamedi-Hagh

Keywords

Bragg's law, crystallography, metamaterials, photonic crystal, switched beam antenna

Subject Areas

Electrical engineering; Electromagnetics; Physics

Abstract

The goal of this thesis was to design a switched beam antenna by applying the principles of crystallography. The main benefit of this approach is that simple design equations can be derived from crystallography and readily applied to the design of a steerable beam antenna. Before using equations from crystallography in an antenna design, the equations are first verified. One of the best known laws of crystallography, namely Bragg's Law, is verified both by software simulation, and experimentally from the radiation patterns of a prototype antenna.

One set of simulations used to verify Bragg's Law involved varying the angles of incidence while changing the plane spacing accordingly to maintain the diffraction condition. The average deviation between the software simulation and the calculated diffracted peak location was 0.8%, confirming Bragg's Law at radio frequency. A prototype antenna was designed using Bragg's Law, and the peak location was verified experimentally. The antenna was designed for use at around 6 GHz.

Having verified that principles from crystallography can be applied at radio frequencies, a switched beam antenna array was designed. The antenna had three possible directions: forward, and +/- 90 degrees relative to the incident beam. The side lobe level was 15.7 dB, and the half power beam width was 2 to 3 degrees.

Download

Share

COinS