Radiometer Information Analysis And Design

As a role instrument, microwave radiometers have been employed in radio astronomy, remote sensing, missile guide and measurement of objective characteristic extensively, with typical mode of all-power radiometer and Dicke radiometer. And radiometer frequency is entended to millimeter wave and sub-millimeter wave, with improvement of electronic technology and microwave and millimeter wave technology , and practical application demand .First, this paper introduces the difference of all-power radiometer and Dicke radiometer sensitivity, and gives normal calibration equation and periodic calibration equation of antenna temperature, and analyses calibration error due to square-law detector illinearity.Secondly, signal flow simulating result of a microwave radiometer is presented with SystemView softwareLast, the principle and circuit of a 94GHz active/passive millimeter wave receiver are discussed in detail. The receiver works on active mode and passive mode in different time. In active mode, the receiver is narrow-band and high sensitive, and IF phase-lock technology is used to stabilize receiving frequency. And in passive mode, the receiver is an all-power millimeter wave radiometer with periodic calibration to improve measure precision.