A High-Power Dual Six-Port Automatic Network Analyzer Used in Determining Biological Effects of Rf and Microwave Radiation

The design, calibration, and performance of a high-power (1-1000 W) automatic network analyzer based on the six-port concept are described for the 10-100-MHz range. Calibration is performed with a length of transmission line as the only impedence standard needed. A 10-mW thermistor mount is the standard of power. Imprecision in measnring reflection coefficient Gamma is 0.0001 in magnitude and 0.005/|Gamma| degrees in phase. Corresponding estimated systematic errors are 0.001 and 0.1/|Gamma| degrees. Imprecision in measuring power is 0.01 percent of range (20 W, 200 W, or 1000 W) with an estimated systematic error of 1.25 percent of reading.