SU1255962A1 - Device for measuring strength of electromagnetic field in conductive medium - Google Patents

Abstract

This invention relates to a radio measurement technique. The noise immunity is increased when measuring in the HF and MF areas. The device contains a measuring unit (VI) 1. A communication line 2 in the form of a coaxial cable 3, a sealed enclosure 4, inside which the amplifier 5 is installed, the sensor 6 of the magnitude of magnitude. .floor grounding 7 ,. conductive medium (PS) 8, electrode (E) 9. If IB 1 is grounded at PS 8, then the eleven magnet field above PS 8 excites current 1 in the circuit formed by the part of the communication line 2 outside the PS 8, IB 1, grounding 7 and sensor 6. Introduction of the E 9 closes the current loop preventing the disturbance circuit from covering the sensor 6. To perform measurements with high accuracy, E 9 is fulfilled with a length of at least one skin layer in the medium and the distance between The sensor 6 and the location E 9 select at least three skin layers in PS 8, the skin layer being determined. on the lower frequency of measurements. 1 il. / (L

Description

one

The invention relates to a technique of radio measurements and can be used to measure the intensity of electromagnetic fields, in particular, the parameters of antennas in a conductive medium.

The purpose of the invention is to increase the noise immunity when measuring in the high and medium frequency region.

The drawing shows the structure: a device for measuring the intensity of an electromagnetic field in a conducting medium.

A device for measuring the intensity of an electromagnetic field (EMI) in a conductive medium contains a measuring unit 1, a line 2 connection in the form of a coaxial cable 3, a sealed enclosure 4, inside which an amplifier 5 is installed, an EMI sensor 6, a grounding 7, conducting Wednesday 8, electrode 9.

Electrode 9 has a length of at least skin layer in conducting medium and is located at a distance of at least three skin layers from sensor 6,

A device for measuring the intensity of the electromagnetic field in a conductive medium works as follows.

Spreading out of conductive medium. 8 HF EMF excites current 1 on the outer surface of the screens of the measuring unit 1 and the surface of the outer conductor of the link 2 of the coaxial cable. In the case of the absence of electrode 9, the current I freely propagates through the coaxial cable to the sensor 6, hits the input of the amplifier 5 and is amplified along with the useful signal, which makes it impossible to separate the useful signal against the background noise. The electrode 9 serves to form a current closure circuit 1, which is developed from the current circuit of the useful signal. Expansion occurs due to the fact that the current 1, | flows along the outer side of the outer conductor of the coaxial cable, and the current of the useful signal I - along the inner side of the outer conductor.

If the measuring unit 1 is grounded to the conductive medium 8, the EMI propagating over the conductive medium excites the current 1 in the circuit formed by the part of the communication line 2 outside the conductive medium 8, by the measuring unit 1 by means of grounding 7 and the sensor 6 With the introduction of electro255962

Yes

9 closes the current loop 1, not

allowing the disturbance contour to cover the sensor 6. To perform measurements with high accuracy, electrode 9 is made at least one skin layer in the medium, and the distance between the sensor 6 and the location of electrode 9 is chosen at least three skin layers in conducting medium 8 The skin-i layer is determined by the lower measurement frequency.

The electrode 9 can be made in the form of a metal tube, put on a coaxial cable. The metal tube is electrically connected to the outer conductor of the coaxial cable and the junction is sealed.

If it is necessary to maintain the flexibility of the coaxial cable, then the electrode 9 is made in the form of a coil of metal wire or tape wound on a coaxial cable.

The use of the proposed device for measuring the intensity of EMI in a conducting medium as compared with the known one provides the possibility of measuring the intensity of EMI in a conducting medium in the MF and HF bands, as well as the ability to measure the parameters of real antenna-feeder devices intended for operation in conducting medium in the MF and HF bands.

The proposed device allows measuring the EMF intensity in a conductive medium at medium and high frequencies, as well as measuring the parameters of antenna-feeder devices intended for operating in a conductive medium in the medium and high frequency ranges.

Claims (1)

Invention Formula A device for measuring the intensity of an electromagnetic field in a conductive medium, containing a series-connected electromagnetic field strength sensor, an amplifier installed in a sealed enclosure, a communication line and a measuring unit located outside the electromagnetic field. The floor and amplifier are placed in a conductive medium, characterized in that, with .. 3 12559624 - the purpose of increasing the noise immunity to the external conductor at a distance when measured in the region of higher than less than three skin layers of conductive medium frequency outer conductor environment for the lower frequency range the line is electrically connected to the measurements from the voltage sensor conductive medium through the input-5 electromagnetic field and has a length Lead Electrode, which is connected to at least one skin layer.