JPH07181206A - Sensor for measuring high frequency current - Google Patents

Abstract

PURPOSE:To enable the switching of the direction of detecting a high frequency current electrically by inverting a bias input from positive to negative or vice versa without mechanical rotation of a sensor. CONSTITUTION:When a positive voltage is applied to a bias input 53, PIN diodes 11 and 12 are turned to a reverse bias and made non-conductive in a high frequency. On the other hand, PIN diodes 13 and 14 are turned to a forward bias and made to conduct in a high frequency. In this case, when a sensor section 2 of a sensor for measuring a high frequency current approaches an object to be measured, the current flowing through the object to be measured is detected only confined to a parallel current companent with conductors 23 and 24. On the contrary, when a negative voltage is applied to the bias input, the diodes 11 and 12 are tuned to a forward bias and made to conductor in a high frequency. ON the other hand, the diodes 13 and 14 are turned to a reverse bias and made nonconductive in a high frequency. In this case a parallel current component alone with conductors 21 and 22 is detected from the current flowing through the object to be measured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency current measuring sensor, and more particularly to a non-contact current measuring method.

[0002]

2. Description of the Related Art A conventional high-frequency current measuring sensor is shown in FIG.

Incidentally, FIG. 3 shows "IEEE TRANSAC".
TIONS ON MICROWAVE THEORY
AND TECHNIQUES, VOL. MTT-2
8, NO. 7, JULY, 1980 ”. In this figure, the probe 10
1 is connected to the core wire of the coaxial cable 102. The coaxial cable 102 is connected to the detector 51.

Next, the operating principle of the first embodiment will be described. As shown in FIG. 4, when the probe 101 is brought close to the object to be measured (conductor 103), the component of the electric field generated by the high-frequency current flowing through the conductor 103 in the same direction as the direction of the probe 101 causes the probe 101 to move. High frequency current is induced. The high-frequency current flowing through the object to be measured can be known by detecting the current with the current detector 51.

FIG. 5 shows "IEEE TRANSACTIO".
NS ON MICROWAVETHEORY AND
TECHNIQUES, VOL. 40, NO. 8, A
UGUST, 1992 ”, which is a second conventional high-frequency current measurement sensor. In this figure, the conductor wire 21 has one end connected to the conductor tube 11 and the other end connected to a coplanar line 33 provided on the side wall of the conductor tube 11.
The coplanar line 33 is connected to the detector 51.

Next, the operating principle of the second conventional example will be described. As shown in FIG. 6, when the object to be measured is present immediately below the sensor, the magnetic field generated by the high frequency current flowing through the object to be measured (conductor 103) is generated so as to surround the conductor wire 21. Therefore, of the high-frequency current flowing through the DUT, the component having the same direction component as the conductor wire 21 is the conductor wire 21.
Is induced by. If this current is detected by the detector 51, the high frequency current flowing through the DUT can be known. Also,
When the device under test exists away from the sensor as shown in FIG. 7, the magnetic field generated by the high-frequency current flowing through the device under test does not surround the conductor wire 21. Therefore, when the object to be measured is far, the high frequency current induced in the conductor wire 21 disappears.

[0007]

In the sensor for measuring high frequency current of Conventional Example 1, since it reacts to the vertical component of the electric field, the magnitude of the high frequency current flowing through the object to be measured can be detected, but up to the direction of the current. Cannot be detected.

Further, the high frequency current measuring sensor of the second conventional example can detect only the magnitude of the high frequency current of the same direction component as the conductor wire 21. Therefore, in order to detect the high-frequency current in the other direction, it is necessary to mechanically rotate the sensor itself by 90 degrees, which requires a long time for measurement.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is not to mechanically rotate a sensor to switch the detection direction of a high frequency current, but to electrically switch the detection direction. Therefore, in the high-frequency current measurement sensor of the present invention, two conductor wires for detecting a high-frequency current are made orthogonal to each other, and PIN diodes are arranged at both ends of each conductor wire,
The detection direction of the high frequency current is switched depending on whether the bias input is positive or negative.

[0010]

The present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the principle of the present invention. The sensor part 2 of the high-frequency current measuring sensor is provided at one end of the conductor tube 1,
The conductor lines 21 to 24 are connected in a cross shape, one ends of the PIN diodes 11 and 13 are connected to the conductor tube 1, and the other ends are connected to the conductor lines 21 and 23, respectively.
4 to the coaxial tubes 31 and 32, and the other end to the conductor wires 22 and 2
4 are connected respectively. The outputs of the coaxial tubes 31 and 32 are
It is connected to the detection output terminal 54 via the detector unit 3 including the high-frequency signal detectors 51 and 52. Furthermore, the coaxial pipe 31,
The output of 32 is connected to the bias input 53 through the bias circuit 4 including the high frequency blocking inductances 41 and 42.

Next, the operation of the present invention will be described. When a positive voltage is applied to the bias input 53, the PIN diodes 11 and 12 are reversely biased, and become non-conductive at high frequencies. On the other hand, the PIN diodes 13 and 14 are forward biased, and are in a conductive state at high frequencies. In this case, as shown in FIG. 2, when the sensor unit 2 of the high-frequency current measuring sensor is brought close to the object to be measured, only the current component flowing through the object to be measured is detected in parallel with the conductor lines 23 and 24. It Conversely, if a negative voltage is applied to the bias input,
PIN diodes 11 and 12 are forward biased,
It becomes conductive at high frequency. On the other hand, PIN diode 1
3 and 14 are reverse biased and are in a non-conductive state at high frequencies. In this case, of the current flowing through the object to be measured, only the current component parallel to the conductor lines 21 and 22 is detected.

Although the coaxial tube is used for extracting the high frequency current, a coplanar line may be used.

In the present embodiment, the conductor tube 1 is composed of a rectangular parallelepiped. However, the conductor tube 1 is not limited to this shape as long as the conductor wires 21 to 24 orthogonal to each other can be connected to one end of the conductor tube 1. .

[0014]

As described above, in the high-frequency current measuring sensor according to the present invention, the detection direction of the high-frequency current can be electrically switched by inverting the positive / negative of the bias input. Therefore, it is not necessary to mechanically rotate the sensor to switch the detection direction of the high frequency current.

[Brief description of drawings]

FIG. 1 is a diagram showing an operating principle of the present invention.

FIG. 2 is a diagram showing an embodiment of the present invention.

FIG. 3 is a diagram showing an example of a first conventional example.

FIG. 4 is a diagram showing an operating principle of the sensor of Conventional Example 1 shown in FIG.

FIG. 5 is a diagram showing an example of a second conventional example.

FIG. 6 is a diagram showing an operation principle in the case where the object to be measured is located directly below the sensor in the second conventional example shown in FIG.

FIG. 7 is a diagram showing an operation principle in the case where there is an object to be measured apart from the sensor in the second conventional example shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 conductor pipe 2 sensor 3 detector part 4 bias part 11-14 PIN diode 21-24 conductor wire 31-32 coaxial line 33 coplanar line 41-42 high frequency blocking inductance 51-52 detector 101 probe 102 coaxial cable

Claims (2)

[Claims] 1. A first pin diode and a direction perpendicular to the first pin diode via four conductor wires orthogonal to each other from a midpoint of one end of a linear conductor tube having a conductor surface made of a conductor. The second pin diode on the tube surface, and the third pin in the linear direction with the first pin diode.
The diode and the fourth pin diode are tangentially connected to the core wires of the first and second coaxial cables, respectively, and the first and fourth pin diodes and the second and third pin diodes are different in direction from the midpoint. A high-frequency current measuring sensor, wherein a bias input and a high-frequency detector are connected to the core wires of the other ends of the first and second coaxial cables that are attached. 2. The high-frequency current measurement sensor, wherein the bias input conducts either the pair of the first and third pin diodes or the pair of the second and fourth pin diodes.