A Real-Time Swept-Frequency Seven Port Reflectometer

A real-time swept frequency reflectometer is described capable of repeatedly displaying a complete 256 point plot of complex reflection coefficient with frequency every 0.2 seconds to an accuracy of 1% and 1°. The microwave design problems occasioned by swept frequency working are described, along with some solutions. The reflectometer is calibrated by a method using only 5 different offset short circuits, and full use is made of the redundant information available from a seven-port reflectometer circuit.