Low Cost, Compact Microwave Reflectometer for Non-Destructive Testing Matthew Rangen and Keith Bruno April 15, 2005 Bradley University Department of Electrical and Computer Engineering

Overview Objective Background Block Diagram Tasks & Schedule Results MATLAB Network Analyzer

Objective The objective of the project is to determine the reflection coefficient of an unknown load by the use of a six- port network analyzer integrated with a workstation.

Background The reflection coefficient can be found by knowing a reference signal and sampling selected power outputs in a micro-strip circuit. With these known quantities and using a specific algorithm, the reflection coefficient can be calculated.

Detailed Block Diagram

Tasks & Schedule

Calibration Process The Calibration process is used to find the complex numbers: These numbers are used to find the gamma of an unknown load.

Calibration Process The Calibration process needs two known items to start the process. 1. Gammas of the Known Loads 2. Power Measurements of the Known Loads Once this is known the calibration process may begin.

Calibration Process By taking the power measurements:

Calibration Process By taking the gammas:

Calibration Process Now by combining the two previous steps. + The calibration process then begins to solve:

MATLAB Work Calibration Flowchart

Measurement Process By using the the known complex numbers found from the calibration process, any gamma can be calculated from an unknown load. This process is very simple compared to the calibration process.

Measurement Process The measurement process needs only one known item. 1. Power Measurements from the unknown load Once this is known, the measurement process begins.

MATLAB Work Measure Flowchart

6-Port Network Analyzer P_one P_twoP_three P_four

90° Hybrid Input PortOutput Port Isolated PortOutput Port } 90° phase- shift difference

90° Hybrid

90° Hybrid Results

90° Hybrid

90° Hybrid Results

Lange Coupler Coupled Port Through Port Input Port Isolated Port

Lange Coupler

Lange Coupler Results

Overview Objective Background Block Diagram Tasks & Schedule Results MATLAB Network Analyzer

Questions? Check us out at: cegt201.bradley.edu/projects/proj2005/sixpna

Calibration Work Calibration Flow Equations

Calibration Work Calibration Flow Equations Part 2

Calibration Work Calibration Flow Equations Part 3

Measurement Work Measurement Equations