Research On Fast Measurement Methods Of Antenna Pattern In Anechoic Chamber

In the wake of rapid development in antenna technology,the antenna measurement technology has become a hot topic.The high accuracy and efficiency antenna measurement methods have become an important part of antenna research and manufacturing.However,the traditional antenna measurement information acquisition method still adopts Nyquist sampling theorem,which increases the complexity of the software and hardware of the measurement system,especially with the development of large phased array,multi-channel,ultra-wideband,and multi-beam antennas.Compressed sensing(CS)sampling theorem breaks the limitation of traditional sampling,the sampling and compression processes are performed simultaneously,and the far-field data is accurately and quickly reconstructed with a small amount of sampled data.In this paper,the fast measurement method of near and far field based on CS is studied from the data acquisition method of antenna pattern.The main research work are as follows:1.Aiming at the problem of large amount of redundant data in the traditional antenna far-field pattern measurement,a CS-based orthogonal analog information conversion(QAIC)system was designed by adding a pair of quadrature bases and a low-pass filter at the front-end,which increases the flexibility of the bandwidth and achieves the effect of fast measurement of the antenna far-field pattern.At the same time,the experimental results of standard horn antenna and pyramid horn antenna show that only a small amount of data can efficiently reconstruct far-field data,which verifies the accuracy of the system.2.Aiming at the problems of large amount of sampling data and long measurement time in the traditional antenna near-field measurement system,a fast measurement system for the anechoic chamber antenna near-field is designed by placing the metasurface in the near-field area of the antenna.The unit in “on” and “off” controlled by the FPGA program,the metasurface code is equivalent to the measurement matrix in CS,by using CS sampling,the effect of the original pattern can be quickly restored.Through the simulation experiment and measured show that only 40% of the measurement data can recover the original signal,and the measurement efficiency is increased by 56%.3.Compared the reconstruction effects of the three common sparse basis and six recovery algorithms used by the system,conducted multiple combined experiments on the CS algorithm,analyzed the measurement error and measurement time,and the best reconstruction performance was exhibited by discrete wavelet transform(DWT)combined with the compressive sampling matching pursuit(COSAMP)algorithm on antenna reconstruction.