METHOD FOR REFLECTION COEFFICIENT MEASUREMENT AND DEVICE FOR METHOD APPLICATION Russian patent published in 2009 - IPC G01R27/06 

FIELD: physics.

SUBSTANCE: invention relates to super high frequency (SHF) engineering; it is intended to measure reflected coefficient of plane samples of radar absorbent coating (RAC) in millimetre, centimetre and decimetre wave band. Method of reflection coefficient measurement consists in calibration of horn measuring antenna by means of RAC reference sample. For this purpose antenna aperture is installed at plane reference sample of RAC. Antenna is moved upwards, along its electrical axis to distance bigger than one fourth of SHF generator's wave length. Simultaneously maximum U1max and minimum U1min amplitude sum values of interfering waves reflected from reference sample and measuring antenna are registered. Possible values of measuring antenna reflection coefficient G1 and G2 are calculated by formulas: G1=(U1max-U1min)/2; G2=(U1max+U1min)/2. Reflection coefficient value different from reflection coefficient value of reference G_REF will be value of antenna reflection coefficient G_a. Calibrated antenna with aperture downwards is installed close onto plane measured sample of RAC with unknown reflection coefficient. For this purpose antenna is moved upwards, along its electrical axis to distance bigger than one fourth of SHF generator's wave length and simultaneous registration is made of U2max and minimum U2min amplitude sum values of interfering waves reflected from reference sample and measuring antenna. Possible values of reflection coefficient of measured RAC sample G3 and G4 are calculated by formulas: G3=(U2max-U2min)/2; G4=(U2max+U2min)/2. Reflection coefficient value different from reflection coefficient value G_A will be value of reflection coefficient G_S of RAC test sample. Device used for this measurement method contains measuring device, SHF cable, measuring antenna, RAC reference sample and device for vertical movement of antenna. Antenna is installed by aperture plane onto plane reference sample. Device for antenna movement contains frame, antenna support, guide arm for antenna movement, measuring scale, bushing, lead screw, worm reduction gearbox, reducer drive shaft and handle of drive shaft.

EFFECT: reduction of measurement error, simplification of method for measurement of reflection coefficient in RAC samples in broad band and provision of this method application for control of RAC reflection coefficient in conditions of series production.

2 cl, 2 dwg