Planar antenna near-field measurement method and system capable of reducing truncation errors

Abstract

The invention discloses a planar antenna near-field measurement method capable of reducing truncation errors, which comprises the steps of obtaining a plane wave spectrum output by a probe through inverse Fourier transform according to an electric field received by the probe; carrying out probe correction; calculating the credible spectral domain of the plane wave spectrum of a to-be-measured antenna according to the emission spectrum of the to-be-measured antenna and a spectral domain filtering function; obtaining an aperture electric field of the to-be-measured antenna through Fourier transform according to the credible spectral domain of the plane wave spectrum of the to-be-measured antenna; performing inverse Fourier transform according to the aperture electric field of the to-be-measured antenna to obtain a scalar form of the plane wave spectrum of the to-be-measured antenna and an electric field located between the to-be-measured antenna and the scanning surface; introducing additional row or column measurement, and calculating an electric field located at the position of an additional row or column probe; calculating an iterative error for each additional row or column measurement; and repeating until the nth iteration error is greater than the (n-1)th iteration error, and terminating iteration. According to the invention, the truncation error problem in planer near-field measurement is reduced based on a band-limited function extrapolation algorithm.

Description

technical field [0001] The present application relates to an antenna measurement technology, in particular to a planar antenna measurement method based on planar near field scanning and capable of reducing truncation errors. Background technique [0002] According to the basic theory of planar near-field measurement, in order to accurately determine the far-field pattern of the antenna under test (far-field pattern, also known as radiation pattern or antenna pattern), in principle, it is required to record the antenna under test The output of the probe (probe) on the previous infinite plane requires that the scanning plane (scanning plane) should be infinite. However, in actual measurement, the scanning plane is always limited, and the field outside the finite scanning plane is assumed to be zero, so the determination of the antenna far-field pattern by the near-field-far-field transformation will inevitably bring errors. This kind of error caused by the limited scanning su...

AI Technical Summary

Problems solved by technology

However, for larger array antennas (array antenna), this will result in too large a scanning area, making near-field testing inefficient

For example, to test a reflector antenna with a working frequency of 30GHz and an aperture of 1.5m, when the scanning surface is a rectangle of 2.4m×2.4m, the sampling interval is 5mm, and the sampling rate is 80mm / s, it takes 7 hours. very low

If the scanning area is reduced, the limited scanning area truncation error will definitely have a greater impact on the measurement results

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