SU985752A1 - Device for sheet material reflection factor - Google Patents

Description

(54) DEVICE FOR MEASUREMENT. COEFFICIENT REFLECTIONS OF SHEET MATERIALS

one

The invention relates to a technique for measuring at ultrahigh frequencies and can be used to measure the reflection coefficient of non-metallic sheet materials.

A device for measuring coefficient, sheet reflection, materials, comprising a transceiver with an antenna connected to a recorder, and a metal sheet, forming a virgin angle angle reflector installed in the radiation field of the antenna, with the possibility of rotation about the axis, passing through its edge, opHSHTiipovanny orthogonal to the direction of the radiation NIN antenna C1.

However, the known device does not produce a high accuracy of measurement.

and the invention of the invention is an increase in measurement accuracy.

The goal is achieved by the fact that the metal sheet and the sheet material under investigation are semi2

ellipses with axes a 7/4 l, b (1.3 1, 5) a, where o and b are small and the major axis of the ellipse, respectively; D - the length of the working wave in free space. FIG. 1 shows the structural scheme of the proposed device; FIG. 2 designs of virgin angle reflector.

The device contains transceiver 1 with antenna 2, connected to recorder 3, and metal sheet 4, which forms a virgin angle reflector with an examined sheet material 5, mounted in the radiation field of antenna 2 with rotation possibility about an axis orthogonal through its edge the direction of radiation of the antenna 2, and the angle sensor 6, with the metal

20 sheet 4 and the sheet material under study 5 has the shape of half ellipses.

The device works as follows.

The microwave oscillations are generated by the transmitting device and radiated by the antenna 2 in the direction of the metal sheet 4 and the sheet material 5 under study. To measure the reflection factor at the required angle, the metal sheet 4 is rotated around the axis by an angle. equal to the angle of incidence on the sample, is the sheet material 5, counted from the normal O to its surface (Fig. 1).

The re-reflected radio waves are received by antenna 2, converted by receiver of transceiver 1 into a signal proportional to the received power, and recorded by recorder 3 simultaneously with the signal of angle sensor 6 of the ninth-degree corner reflector, carrying information about the angle / .20

The reflection coefficient measurement is performed in two steps. At the first stage; measured is the purity P reflected from the corner reflector formed by the metal sheet 4 and the 25 sheet material 5 being examined. In the second stage, the sheet material 5 being replaced is replaced by a metal sheet of equal size and the reflected power PO is measured again. The sought reflection coefficient PCtp) is defined as the ratio of the measured powers P and P. To improve the measurement accuracy, the minimum size O of the metal sheet 4 and the sheet material 5 is selected: 4L, which provides a significant excess of the reflected power over the power dissipated the edges of the metal sheet 4 and the sheet material 5, which is the source of the error,

To further reduce the influence of the contribution of the scattering on the edges, the metal sheet 4, re-reflected from 1 signal, and the sheet material 5 under study, are given a semi-ellipse cut along the minor axis with a ratio of axes b (1.3 - 1.5) s (.

The proposed device allows for measuring accuracy and extending the range of measured reflection coefficients in the direction of small values. F o rmula of the invention

A device for measuring the reflection coefficient of sheet materials, comprising a transceiver with an antenna connected to the recorder and a metal sheet forming a virgin angle angle reflector installed in the radiation field of the antenna rotatably with the test sheet material. with respect to the axis passing through its edge, oriented orthogonal to the direction of radiation of the antenna, characterized in that, in order to increase the accuracy of measurements, the metal sheet and the sheet material under study are in the form of semi-ellipses with axes a, 4, b (1.3-1.5) s ( where a and b are small and large are the axes of the ellipses, respectively, A is the length of the working wave in free space. Sources of information taken into account in the examination

1. USSR author's certificate No. 511552, cl. G 01 R 27 / O6, 1974 (prototype) ..

Claims (1)

Claim A device for measuring the reflection coefficient of sheet materials, containing a transceiver with an antenna connected to the recorder, and a metal sheet forming a ninety-degree angle reflector with the studied sheet material, mounted in the radiation field of the antenna with the possibility of rotation about an axis passing through its edge, oriented orthogonally to the radiation direction antennas, characterized in that, in order to improve the accuracy of measurements, the metal sheet and the studied sheet material have of semi-ellipses with axes a 4 X, b = (1.3-1.5) a, where a and b are the small and large axes of the ellipse, respectively, λ is the length of the working wave in free space.