采用三音校准法的星载多波束天线校准系统

为了解决宽带多波束天线系统中常规校准不能兼顾工作频带的低频段和高频段的问题,根据星载多波束天线系统的特点,提出了三音校准法.采用3个单音信号作为校准信号对多波束系统的通道进行测量,以二次拟合得到全工作带宽内的通道幅相特性曲线,并采用多次测量形成拟合点,降低了测量误差的影响；再以拟合的特性曲线的逆函数进行通道幅相补偿,使全带宽内通道特性曲线成为水平直线,从而完成了单通道的校准；最后以补偿项补偿通道间幅相差异,从而达到通道间误差校准的目的.并将三音校准法应用到卫星天线的近场校准和内部校准2种校准系统中.结果表明:三音校准法比传统的单点校准和分段式校准更利于通道间误差的校准,能够有效地抑制通道的不一致性.

Multi-beam antenna calibration system of satellite by triple-toned calibration method

To solve the asynchronous considering for low and high frequency of common calibration,the triple-toned calibration method was proposed based on the characteristics of multi-beam antenna system of satellites.The channels of multi-beam system was measured by three single tone calibration signals to ca-librate the full band amplitude-phase errors with quadratic fitting.The measurement errors were decreased effectively by fitting dots from repetitive measurements.The channel amplitude-phase response was compensated by the inverse function of the fitting characteristic curve.The single channel calibration was realized when the full band characteristic curve was turned to horizontal line.The interchannel errors were calibrated and compensated by amplitude-phase compensating term.The triple-toned method was applied in two calibration schemes of satellite antenna,near-field and far-field calibration.The results show that the proposed method can effectively solve the problem of channel mismatch.