JPH08271563A - Performance measuring apparatus for high frequency device - Google Patents

Abstract

PURPOSE: To realize accurate measurement in a short time without dismantling the component by observing the noise signal spectrum of receiving signal obtained from an output terminal when a pseudo-signal is inputted to the input terminal of a high frequency device. CONSTITUTION: A pseudo-signal generation means 2 generates a pseudo-signal having power corresponding to 60% or above of the rated current of a circulator 1, for example. When it is fed to the transmission terminal of the circulator 1, the pseudo-signal is outputted to an antenna terminal and terminated and consumed by a dummy load 3. A part of the pseudo-signal inputted to the circulator 1 is attenuated and outputted to the receiving terminal thereof. A receiving filter 4 removes signal of undesired bands and a low noise amplifier 5 amplifies a signal appearing at the receiving terminal by 72 dB, for example, before feeding to a spectrum analyzer 6. When the circulator 1 is oscillated using a vibrator, relatively small crack and the like are rendered conspicuous positively and detected easily.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring the performance of a high frequency device such as a circulator or an isolator having a ferromagnetic material as a constituent element.

[0002]

2. Description of the Related Art In a duplex radio apparatus that performs communication by changing transmission and reception frequencies, a circulator that separates a transmission signal and a reception signal is indispensable. Ferromagnetic materials such as ferrite are used for high frequency devices such as circulators and isolators in order to output or take out high frequency signals with directionality. For example, in the above-mentioned circulator, as shown in FIG. 3, the directionality of the input / output signal is determined by the direction of the magnetic field of the ferromagnetic material.
The signal input from the transmission end a is output to the antenna end b, and the signal input to the antenna end b is output to the reception end c.

A general structure of a circulator that functions as described above is shown in FIG. The circulator has a laminated structure in which the center of the strip line 8 is sandwiched by ferromagnetic materials 7 such as ferrite, and these are further sandwiched by ground plates 9, and the ground plates 9 and 9 are fixed to each other by screws 12 to make them ferromagnetic. Body 7
The strip line 8 is held under pressure, a magnet 10 is provided in a recess provided in the center of the ground plate 9, and the periphery of the ground plate 9 is screwed and sealed by a yoke 11.
Therefore, the ferromagnetic material 7 receives the magnetic field from the magnet 10 to give directionality to the input signal.

However, since the circulator has the above-mentioned laminated structure, the ferromagnetic material 7 may be cracked or cracked when a strong impact is applied during assembly or transportation in the manufacturing process. Further, similarly, cracks or the like often occur depending on the tightening condition when the ground plates 9, 9 are screwed together. When a signal is passed through the circulator in which the ferromagnetic material is cracked as described above, electric discharge is generated in the cracked or cracked portion of the magnetic material, and noise is generated in the output.
Further, in the circulator, since the ground plate 9 is made of aluminum and the yoke 11 is made of iron, if the screws between the ground plate and the yoke are not sufficiently screwed, the earth potential changes due to the rubbing of dissimilar metals, which causes noise. Occurs. However, since these noises do not always occur and often occur suddenly, it is difficult to find such defects and the quality is unstable. Conventionally, the only way to confirm the quality of a circulator was to disassemble it. Therefore, when such a defective circulator is incorporated in the wireless device, there is a problem that noise is mixed in the received signal due to the noise, and the performance of the wireless device is degraded.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and is capable of easily reducing the quality of a high frequency device having a ferromagnetic material caused by cracking or cracking of a magnetic material without disassembling the component body. It is an object of the present invention to provide a device which can be accurately checked and can be measured in a short time.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention comprises a pseudo signal generating means connected to a transmission end of a high frequency device having a ferromagnetic material as a constituent, and a pseudo load connected to an output end of the high frequency device. An input terminal of the high-frequency device, which comprises a reception filter connected to a branch signal end of the high-frequency device, an amplifier connected to an output end of the reception filter, and a frequency spectrum measuring unit connected to an output end of the amplifier. The quality of the performance of the high-frequency device is determined by observing the noise frequency spectrum of the received signal obtained from the output end when the pseudo signal is input to. Further, the present invention is characterized in that the pseudo signal power is 60% or more of the rated power of the high frequency device, and the pseudo transmission signal is measured by using CW or a pulse wave. Further, the present invention is characterized by using a vibrator for vibrating the high frequency device or a constant temperature bath for changing the temperature of the high frequency device.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail based on the embodiments shown in the drawings. FIG. 1 is a block diagram showing an embodiment of a performance measuring apparatus for a high frequency device according to the present invention, which is a circulator as an example of the high frequency device. In this measuring system, the pseudo signal generating means 2 is connected to the transmitting end of the circulator 1, the dummy load 3 is connected to the antenna end, and the receiving filter 4 is connected to the receiving end. Further, a low noise amplifier 5 is connected to the output end of the reception filter 4, and a spectrum analyzer 6 is connected to the output end of the low noise amplifier. The circulator performance is measured as follows using the measurement system configured as described above.

First, a pseudo signal (CW) is generated by the pseudo signal generating means 2. The power is set to, for example, 60% or more of the rated power of the circulator, and when this is input to the transmission end of the circulator, the pseudo signal is output to the antenna end and terminated and consumed by the dummy load 3.
Part of the pseudo signal input to the circulator is attenuated,
It is output to the receiving end. The reception filter 4 removes unnecessary band signals and may leak the low noise amplifier if a large amount of transmission energy leaks. Therefore, the reception filter 4 should not be directly input to the low noise amplifier. It is necessary to remove it in 4. In the low noise amplifier 5, the signal appearing at the receiving end is, for example, 72
The signal is amplified by about dB and supplied to the spectrum analyzer 6.

FIG. 2 is a diagram showing the spectrum of the receiving end signal measured by the spectrum analyzer. When the magnetic material has no cracks or cracks, the noise in the receiving filter band becomes flat as shown in (a). However, if the magnetic material is cracked or cracked, a pulse appears on the screen or the noise level rises abnormally as shown in (b) or (c). That is, in a defective circulator as described above, grounding defects such as a ground plate and a yoke occur due to cracks and cracks in the magnetic material, and various noises are generated. Can be observed through. The pulse-shaped spectrum components present at the left ends of FIGS. 9A, 9B and 9C are leakage components of the transmission signal.

In the circulator performance measuring apparatus described above, the circulator 1 is equipped with a vibrator.
By vibrating, defects that are relatively difficult to find such as relatively small cracks can be positively revealed and easily detected. By doing so, in addition to the case where the magnetic body has a slight crack, etc., the magnetic body is normal but the circulator with a poor grounding, which generates noise only when vibrating, is not defective. Can be detected. Further, if the device to be measured is stored in a high temperature tank and a temperature change is applied, a defect manifested by the temperature change can be detected. Furthermore, it has been confirmed that if a pulse signal is used as the pseudo signal, the same effect as applying mechanical vibration / impact to the circulator can be obtained.

In the above embodiments, an example of a circulator was described as a high frequency device, but the present invention is not limited to a circulator, but is applicable to all high frequency devices using magnetic materials such as isolators and phase shifters. If there is a crack in the body, damage such as a crack, or a grounding failure such as a ground plate or a yoke, which causes a sudden change in the electrical output, the quality of the product is determined by the measuring method according to the present invention. be able to. Although some phase shifters and the like have a pair of input and output ends, in this case, the output of the output end may be appropriately branched and the waveform or spectrum may be observed by the same spectrum measuring means.

[0012]

Since the present invention measures the circulator as described above, the performance can be reliably measured without disassembling and destroying the circulator body. Furthermore, if an acceleration test is performed using a vibrator or a high temperature tank, the measurement can be performed in a short time. Therefore, it has a great effect in improving the measurement accuracy and shortening the measurement time as compared with the conventional case.

[0013]

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of a high-frequency device performance measuring apparatus according to the present invention.

FIG. 2 is a diagram showing a spectrum of a receiving end signal measured by a spectrum analyzer according to the present invention.

FIG. 3 is a block diagram illustrating a function of a circulator.

FIG. 4 is a sectional view showing a general structure of a circulator.

[Explanation of symbols]

1 ... Circulator 2 ... Pseudo signal generating means 3 ... Dummy load 4 ... Reception filter 5 ... Low noise amplifier 6 ... Spectrum analyzer 7 ... Ferromagnetic material 8 ... Strip line 9 ... Ground plate 10 ...
Magnet 11 ... Yoke 12 ...
screw

Claims (6)

[Claims] 1. A pseudo signal generating means connected to a transmitting end of a high frequency device having a ferromagnetic material as a component, a pseudo load connected to an output end of the high frequency device, and a branch signal end of the high frequency device. The reception filter, an amplifier connected to the output end of the reception filter, and frequency spectrum measuring means connected to the output end of the amplifier, and the output end when a pseudo signal is input to the input end of the high-frequency device. An apparatus for measuring the performance of a high-frequency device, characterized by determining the quality of the performance of the high-frequency device by observing the noise frequency spectrum of the received signal obtained from the above. 2. The high frequency device measuring apparatus according to claim 1, wherein the high frequency device is a circulator. 3. The performance measuring apparatus for a high frequency device according to claim 1, wherein the pseudo signal power is 60% or more of the rated power of the high frequency device. 4. The performance measuring apparatus for a high frequency device according to claim 1, 2 or 3, wherein the pseudo signal is a CW or a pulse wave. 5. A performance measuring apparatus for a high frequency device according to claim 1, 2 or 3, further comprising a vibrator for vibrating the high frequency device. 6. The high frequency device is placed in a constant temperature bath so as to be capable of changing the temperature.
The performance measuring apparatus for a high frequency device according to 2 or 3.