Low cost precision reflectometer

Sammanfattning: This Master Thesis contains an evaluation of the six-port reflectometer (SPR), an alternative method for measuring reflection. This technique allows the measurement ofcomplex reflection using only scalar detectors. Obtaining both amplitude and phase information gives the possibility to make corrections for systematic errors such as feeder cable loss and directivity error. The report contains a literature study including the six-port reflectometer technique as well as a historical overview of reflection measurement techniques. Further more it contains simulation results of parts of the design as well as of the complete system. The calibration algorithm of the SPR is presented step by step with an improvement made in order to reduce the number of calculations. Measurement results of the reflection measurements are presented as a comparison to the result obtained from a network analyzer. The simulations showed high accuracy when simulating variations in the return loss of the loads as well as variations of the input signal frequency. The simulations also gave some indications on how to affect the accuracy of the reflection measurements. Measurements showed high accuracy when measuring unknown loads with changing return loss. Variations of the input power also yielded a good result. Measurements performed with the input signal frequency variated failed to show the same high accuracy as in the simulations. However, there are some improvements suggested to increase the accuracy in a presumptive product.