Simultaneous electromagnetic measurement using a parallel modulated probe array

A simultaneous measurement method using a parallel modulated probe array is proposed to measure the electromagnetic field radiated by antennas at different locations simultaneously. Each modulated probe is excited by a local signal with different frequency, so that the received intermediate frequency (IF) signal contains different frequency components which indicate the relative magnitude of the radio-frequency signal at positions of the probes, and all the IF components are measured simultaneously by a broadband microwave receiver. The effect of the local signal on the received IF signal and interaction effect between the probe array and the measured antenna are investigated. The accuracy of the method is shown by measuring the antenna radiation pattern. A 3-D antenna radiation measurement system based on the present method is also developed. The performance of the system is demonstrated by measuring the radiation efficiency of antennas.