METHOD TO MEASURE COEFFICIENT OF REFLECTION OF FLAT REFLECTOR IN MICROWAVE RANGE AND DEVICE FOR ITS REALISATION Russian patent published in 2013 - IPC G01R27/06 

FIELD: measurement equipment.

SUBSTANCE: previously calibration is performed with the help of a flat reference reflector, then perpendicularly to the axis of the mirror in the middle of the distance L_foc between the phase centre of the radiator and the mirror focus they install a reference reflector with available coefficient of reflection of G^REF, the coefficient of reflection $$S_{11}^{ref}\left(f\right)$$ is measured in the same frequency band, and the third coefficient $$A_3^{ref}$$ of generalised polynom $$P^{ref}\left(f\right)={\displaystyle \sum A_n^{ref}\exp \left(-jn2\pi f{L}_{foc}/c\right)}$$ is determined, which approximates the difference of measured coefficients of reflection referred to the radiator aperture: $$P^{ref}\left(f\right)\approx \left(S_{11}^{ref}\left(f\right)-S_{11}^{ta}\left(f\right)\right)\exp \left(j2{\phi }_{tr}\left(f\right)\right),$$ afterwards instead of the reference reflector they install a tested reflector, the reflection coefficient is measured at the inlet of the measuring antenna $$S_{11}^{tr}\left(f\right)$$ in the same frequency band, and the third coefficient of the polynom $$P^{tr}\left(f\right)={\displaystyle \sum A_n^{tr}\exp \left(-jn2\pi f{L}_{foc}/c\right)}$$ is determined, which approximates difference of reflection coefficients $$S_{11}^{tr}\left(f\right)-S_{11}^{ta}\left(f\right),$$ referred to the $$A_3^t$$ radiator's aperture $$P^{ref}\left(f\right)\approx \left(S_{11}^{tr}\left(f\right)-S^{ta}\left(f\right)\right)\exp \left(j2{\phi }_{tr}\left(f\right)\right),$$ the coefficient of reflection of G^TR of the tested reflector is determined using the formula $$G^{tr}=G^{ret}\sqrt[3]{\left|A_3^{tr}\right|/\left|A_3^{ref}\right|}.$$ The device for measurement of the reflection coefficient comprises a metering antenna, a reference flat reflector, a device for measurement of complex amplitude of the reflected signal, a microwave cable, a calculator. At the same time the antenna is made in the form of an axisymmetric parabolic mirror with a radiator in its top, and at the edge of the mirror there is a radio transparent fixator with a mechanism of alignment of the flat reflector position.

EFFECT: higher accuracy of measurement of reflection coefficient.

2 cl, 5 dwg