Design and analysis of TEM horn antenna for GPR applications

Abstract

Ground penetrating radar (GPR) is a technique used to probe the ground. This technique is positioned top among all existing geophysical techniques. Applications of GPR are enormous and are ranging from planetary exploration to the detection of buried mines. In GPR to get high resolution and to get the wave traveled through deeper distance inside the earth, the transmitting antenna (Tx) must transmit the narrow width pulse signal into the ground where objects are hidden. This thesis presents the work on the design of TEM horn antenna. For this application A Compact Double-Ridged Horn Antenna from the family of horn antennas with an ultra-wide band (0.827–4.5)GHz is designed & simulated. Both the time domain and frequency domain requirements are satisfied by this antenna. This antenna is simulated using Computer simulation technology (CST) microwave studio. This antenna is test simulated in time domain solver with feeding via 50 Ω SMA and also tested in both thermal solver & mechanical solver to check for its malfunction. The variation of characteristic impedance across the antenna structure is gradually varied from 50 Ω to 377 Ω. In this thesis we will go through the steps how the lower range frequencies can be achieved with TEM horn & in what way the Linear TEM horn is transformed to Compact Double-Ridged Horn Antenna. This thesis also includes an explanatory part on both theoretical & simulated version of Linear TEM horn antenna, Double ridged horn antenna, Compact Double-Ridged Horn Antenna & Double-Ridged Horn Antenna in GPR scenario along with the simulation results.