Accurate Measurement Techniques for 75 Ohms Antenna with 50 Ohms Vector Network Analyzer

摘要

This paper described accurate measurement techniques of a 75 ohms antenna with 50 ohms vector network analyzer (VNA). The antenna under test (AUT) was a commercial antenna (SP-073 DTV antenna). The analysis techniques used three basic principles namely the return loss, Friis formula and absolute gain Eq.s to solve the differences of characteristics impedance (Z_O). The experimental results showed that although the Z_O of AUT was different from the VNA it could also measure the impedance, radiation pattern and gain without the 50 to 75 Ohms converter. While the use of converter led to unacceptable results.