JP3102709B2 - Electronic element measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device measuring apparatus, and more particularly, to a four-terminal pair calibration of a three-terminal measuring instrument. However, the three-terminal pair measuring device referred to in the present specification has the same basic operation as that conventionally called a four-terminal measuring device, and is realized by using three terminal pairs.

[0002]

2. Description of the Related Art In a conventional three-terminal pair measurement, the measuring device 10 shown in FIG. The terminal pairs 12, 14, 16, and 18 generally have a coaxial structure in which a jacket and a core wire are paired. The outer sheaths of the terminal pairs 14 and 16 are connected and connected to the circuit ground of the measuring device 10. The voltage between the core wires of the terminal pairs 14 and 16 is measured differentially. As the signal source 40, a DC or AC voltage source 42
And the ammeter 44 can be connected in series to the circuit ground. Of course, it may be a current source. The cables 22, 24, 26 are also coaxial, with one terminal of each being connected to a terminal pair 12, 14, 16, respectively.
The other terminal is connected to terminals 32 and 34 of device under test 30. On the device under test side, the core wires of the cables 22 and 24 are connected to one terminal 32 of the device under test 30.
And the core of the cable 26 are connected to the other terminal 34 of the device under test 30, and the jackets of the cables 24 and 26 are connected to each other as close as possible to the device 30 to be measured.

The signal source 40 of the measuring device 10 is connected to the core wire 122 of the terminal pair 12 and the jacket 124, and supplies a signal current to the device under test 30. Further, the signal source 40 transmits the signal current value to the control calculation means 60. The voltage measuring means 50 is generally configured as a differential voltmeter, measures the voltage between the core wires 142 and 162 of the terminal pairs 14 and 16, and transmits the measured value to the control calculating means 60.

The control calculation means generally includes a computer, but in connection with the present invention, the signal current value (I)
And the measured voltage value (V), and the function of obtaining the complex impedance Z (= V / I) of the measured electronic element from the measured voltage value (V). Calibration of the measuring instrument is performed by using a known standard element. It has a function of performing correction and the like. Since the functional performance of these control calculation means 60 is well known, description thereof will be omitted. Magnetic cores 126, 146, and 166 are loaded on the core wires and the sheaths of the terminal pairs 12, 14, 16 so as to form a balun. Such a measuring method is awarded when the impedance of the electronic device under test is low.

[0005] In contrast to such a measuring method, a measuring method of an electronic element known as a four-terminal pair measuring method has become widespread. Many measuring instruments of the four-terminal pair measuring method include, for example, an HP4292ALF impedance analyzer commercially available from Yokogawa Hewlett-Packard Co., Ltd. Standards for calibration of a four-terminal pair measuring instrument have been prepared accordingly, and if they are effectively used even in three-terminal pair measurement, the types of the standard instruments can be reduced. Along with this, the development of the standard becomes more efficient, and therefore, it becomes easier to develop a more advanced standard. HP16380A and HP16380 commercially available from Yokogawa-Hewlett-Packard Co., Ltd.
C standard capacitor set and HP1604A calibration R-
There is L standard.

[0006] As shown in FIG.
It has four terminal pairs 82, 84, 86, 88, whose jackets are integrated and houses a standard element 90 therein. The core wires of the terminal pairs 82 and 84 are connected to one terminal 92 of the standard element 90, and the core wires of the terminal pairs 86 and 88 are connected to the other terminal 94 of the standard element 90. The standard device 80 is often stored in a case 100 made of an insulator. In order to measure the four-terminal pair standard device 90 with the conventional three-terminal pair measuring device, three coaxial cables are prepared, and the terminal pairs 12, 14, 16 and the terminal pairs 82, 84, 86 are prepared.
And the terminal pair 88 must be short-circuited.
This is generally the case for terminal pairs 12, 14, 16 or 82,
This is because 84, 86, and 88 are generally arranged on the same plane. As described above, it is very troublesome to measure a four-terminal-pair standard device with a conventional three-terminal-pair measuring device, and there is also a deterioration in calibration accuracy due to the cable used.

[0007]

OBJECTS OF THE INVENTION It is therefore an object of the present invention to provide a three terminal pair measuring device with a shorted terminal pair to overcome the above disadvantages.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, a fourth terminal pair is newly provided in a measuring apparatus, and a four-terminal pair standard device is arranged so as to be directly measured.

[0009]

FIG. 1 shows an electronic device measuring apparatus 10 according to an embodiment of the present invention. A terminal pair 18 is newly provided in the conventional three-terminal measuring apparatus. The terminal pair 18 is a short-circuited terminal pair whose core wire and jacket are short-circuited. With the measuring device 10 of the present invention, a four-terminal pair standard device 80 is used for calibration.
When measuring the terminal 12, 14, 16, 18 are connected to the corresponding terminal pair 82, 84, 86, 88, their envelope comrades, core wire comrades conductive.

In the measurement shown in FIG. 1, the wiring connecting the jacket of the cable 22 and the terminal 34 may be cut at the point "X" and short-circuited by the cable 28 and the terminal pair 18, but the impedance of the wiring may be considered. Rises to cause a common mode in the voltmeter 50, which is not preferable. It is well known that the cables 24 and 26 are twisted in order to reduce errors of the voltmeter due to the generation of electromotive force due to an external magnetic field.

[0011]

As described in detail above, by implementing the present invention, a four-terminal standard can be directly used for calibration of a three-terminal measuring apparatus, so that the types of other standard that are convenient to use can be reduced. It is possible to do. In the above description, the device under test 30
Is a two-terminal element, but may be a four-terminal element in general. For example, in the case of a transformer, if a primary winding is connected between the core of the cable 22 and the jacket, and a secondary winding is connected between the cores of the cables 24 and 26, mutual inductance is obtained.

[Brief description of the drawings]

FIG. 1 is a schematic circuit diagram of an electronic device measuring apparatus according to one embodiment of the present invention.

FIG. 2 is a schematic circuit diagram of a four-terminal pair standard device.

[Explanation of symbols]

10: Electronic element measuring device 22, 24, 26, 28: Cable 40: Signal source 50: Voltage measuring device 60: Control calculation means 80: 4-terminal standard device 90: Standard device

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G01R 27/02 G01R 27/28 G01R 35/00

Claims (3)

(57) [Claims] 1. A fourth terminal pair comprising a first pair of terminals to which a signal source is connected, a second pair of terminals to which a voltmeter is connected, and a shorted pair of terminals, and an output of the signal source. An electronic device measuring apparatus comprising: a calculating unit that determines an impedance of an electronic device to be measured from a current value and a measured voltage value of the voltmeter. 2. The method of claim 1, further comprising:
To each terminal connected to each of the fourth terminal pairs
The electronic element measuring device according to claim 1, further comprising a four-terminal pair standard element having a pair. 3. The core wire of said first, second and third terminal pairs.
And the outer shell are magnetic cores to form a balun
Claim 1 or Claim characterized in that it is loaded
Item 3. The electronic element measuring device according to Item 2.