Automatic Measurement System for Focal Spot of Broadband Focusing Antenna Based on Electrical Probe Scanning

-An automated measurement system of focal spot and focal distance of focusing antenna is proposed in this paper, using the sensing characteristics of electric probe on focusing near field of antenna, controlling the scanning of VNA and electric probe synchronously by using personal computer to carry out the automatic measurement of focal distance and focal spot. After measuring the 2-18 GHz lens antenna with this system, the relative errors of focal length and focal spot measurement are within 8% compared with the simulation results, validating the system with well measurement accuracy.