Antenna Measurements by One-Path Two-Port Calibration Using Radio-on-Fiber Extended Port Without Power Supply

We have developed a prototype of a novel extended port for an RF vector network analyzer (VNA) below 2 GHz, employing a radio-on-fiber technique in order to overcome several problems in antenna measurements. Specifically, it excludes unwanted effects associated with the metallic cables connecting antennas to the VNA. Using our system, we can make antenna measurements in one-path two-port calibration without using the metallic cables. All components need neither power supply nor bias circuit. To demonstrate the capability of the proposed system below 2 GHz, we have measured the uarr-parameters between two biconical antennas. #n agrees well with that obtained using a conventional VNA system. The agreement is within 0.03 (0.013 on average). The dynamic range of S2i is found to be more than 45 dB (56 dB on average)