A Low-Cost PC Controlled System for Measurement of Vector Reflection Coefficient in ISM Band

This paper describes design of a prototype of a very low-cost ISM band reflectometer for measurement of a vector reflection coefficient. The device is based on integrated circuit AD8302 by Analog Devices. Switched phase shifter is used to resolve the problem of ambiguity of the sign of the phase shift. The system is controlled by a dedicated digital circuit and PC user interface. The system was designed for the band 2.3 GHz to 2.6 GHz as an inexpensive measurement alternative in manufacturing and maintenance of heating and telecommunication systems in that band. The paper provides accuracy analysis indicating the accuracy levels which can be expected from devices of that class.