KR950000666B1 - Monitoring alert device of hi-fi amplifier - Google Patents

Abstract

The apparatus automatically controls the ouput level of the high-power amplifier used in wireless communication and provides the alarm when the output is over the critical level. The apparatus comprises a high frequency amplifier (10), two directional couplers (20,60), a three-terminal circulator (50), two wave detectors (30,70), an automatic controller (40) of the output level, and the alarm circuits (60) as shown in the figure. This apparatus provides the improved efficiency and reliablity of the device due to reducing the output loss of the high power amplifier.

Description

Monitoring alarm device of high power amplifier

1 is a block diagram of a conventional monitoring alarm device.

2 is a block diagram of a monitoring alarm device according to the present invention.

3 is a detailed circuit diagram of one embodiment of the alarm circuit 90 during the second.

* Explanation of symbols for main parts of the drawings

10: high frequency amplifier 20,60: first and second directional coupler

30,70: first and second detector 40: automatic output level control unit

50: circulator 80: pseudo load

90: alarm circuit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high output amplifier for use in a wireless transmission apparatus, and more particularly, to a supervisory alarm apparatus for generating an alarm signal according to an operating state by measuring an output power level and a reflected signal level of a high output amplifier.

In general, in a wireless communication system, the transmission output power of a high output amplifier used in a wireless transmission device varies due to changes in power supply voltage, ambient temperature, and high frequency load.

As a countermeasure against this, an automatic output level control circuit is used to stabilize the transmission output. At the same time, the transmission output power level is measured and compared with the existing level to generate an alarm signal according to the operating state. The generated alarm signal is sent to the controller of the system to inform the controller of the operating state of the high power amplifier. Accordingly, the use of the high output amplifier can be stopped when an abnormal operation occurs in which the transmission output power level of the high output amplifier is lowered by the set reference level.

A supervisory alarm for a conventional high power amplifier is typically configured as shown in FIG. The high frequency input signal for transmission in FIG. 1 is amplified by the high frequency amplifier 1 and passed through the first and second directional couplers 2 and 5 in a band other than the transmission frequency band in the transmission band filter 8. The generated signal is removed and then transmitted wirelessly through the antenna 9. In this case, the first and second directional couplers 2 and 5 detect and induce the output high frequency signal of the high frequency amplifier 1. The detected high frequency signals are detected by the first and second detectors 3 and 6 and converted into DC voltages, respectively. The automatic output level control unit 4 maintains a high frequency output power level by controlling the supply power of the high frequency amplifier 1 by comparing the converted DC voltage of the first detector 3 with a preset reference voltage.

At this time, the automatic output level control unit 4 turns on or turns on the high frequency amplifier 1 by a transmission control signal applied from the control unit of the system, that is, a signal for controlling the driving of the high frequency detector 1 in response to the presence or absence of the transmission operation. Turn it off.

The alarm circuit 7 detects the operating state of the high output amplifier by inputting and comparing the converted DC voltage of the second detector 6 with the transmission control signal, and sends the alarm signal to the controller of the system. In this case, the portion (indicated by the dotted line) composed of the high frequency amplifier 1, the first directional coupler 2, the first detector 3, and the automatic output level control unit 4 corresponds to the high output amplifier, and the second directional coupler ( 5), the part comprised of the 2nd detector 6, the alarm circuit 7, the transmission band filter 8, and the antenna 9 corresponds to a load circuit. And it is usually connected as a coaxial cable between the high output amplifier and the load circuit.

As described above, the first directional coupler 2, the first detector 3, which is a signal detection means for the automatic output level control of the high power amplifier, and the second directional coupler 6, the signal detection means for the alarm, 2 detectors 6 are used separately, respectively.

Therefore, the insertion loss and the reflection loss are generated to actually increase the output power level of the high output amplifier, there is a problem that the heat generation increases due to the increase in the output power level.

In addition, there is a problem that it is impossible to measure the reflected signal generated between the output of the high output amplifier and the input of the signal detection means for the alarm.

Accordingly, an object of the present invention is to provide a monitoring alarm apparatus capable of simultaneously performing automatic output level control of an output amplifier and signal detection for an alarm with one signal detecting means.

Another object of the present invention is to provide a supervisory alarm device capable of generating an alarm signal according to an operating state by simultaneously transmitting the high frequency output power of a high output amplifier to a load circuit without loss and simultaneously measuring the output power level and the reflected signal power level. .

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram of a high-power amplifier supervision and warning device according to the present invention, wherein the first directional coupler 20 and a surge between the output terminal of the high frequency amplifier 10 and the transmission band filter 100 for amplifying a high frequency input signal. A circulator 50 is connected in series, and a high frequency signal detected by being induced by the first directional coupler 20 is applied to the first detector 30. The output terminal of the first detector 30 is commonly connected to the automatic output level control unit 40 that controls the high frequency amplifier 10 and one input terminal of the alarm circuit 90.

Accordingly, the output of the output power detecting means composed of the first directional coupler 20 and the first detector 30 to detect the output power of the high frequency amplifier 10 is an automatic output level control unit 40 and an alarm circuit 90. Are commonly used.

Meanwhile, the circulator 50 is a general three-terminal circulator that impedance-matches a signal input from the first directional coupler 20 to the transmission band filter 100 and transmits the signal due to impedance mismatch. The reflected signal reflected from 100 is separated and applied to the second directional coupler 60. The high frequency signal detected by being induced by the second directional coupler 60 is applied to the alarm circuit 90 via the second detector 70. In addition, a pseudo load 80 is installed between the second directional coupler 60 and the ground, so that the circulator 50 consumes the separated reflection signal. The pseudo load 80 may use a resistor.

In addition, a transmission control signal applied from a control unit of the system is commonly applied to the automatic output level control unit 40 and the alarm circuit 90 to control the driving of the high frequency amplifier 10 in response to the transmission operation.

The first and second directional couplers 20 and 60 are typically composed of two microstriplines with impedance matching to induce a high frequency signal at a constant level according to the spacing between the two microstriplines. It is a known device for detecting by using the same method as the first and second directional couplers 2 and 5 in the above-described conventional first drawing. The first and second detectors 3 and 6 are conventionally known as a device for converting the induced signal into a voltage of a direct current component, which is generally composed of a linear fast switching detector diode. The same as the second detectors 3 and 6.

In addition, the portion of the configuration of FIG. 2 except for the transmission band filter 100 and the antenna 110 (indicated by the dotted lines) corresponds to the high output amplifier, and the transmission band filter 100 and the antenna 110 correspond to the load circuit. do.

3 is a detailed circuit diagram of one embodiment of the alarm circuit 90 in the configuration of FIG. 2, which is composed of the resistors 312-316 and includes the first directional coupler 20 and the first detector 30. A voltage divider 302 for dividing the output detection voltage output from the power detecting means to the automatic output level control unit 40 by a constant voltage, operational amplifiers 318 and 330 and resistors 320 to 328 and 332 to detect the divided output. A first comparator 304, an exclusive oragate 336, a resistor 334, 340-344, 348-354, a capacitor 338, and an operational amplifier 346 that amplifies the voltage and compares it with a set reference voltage. A detection control unit 306 for comparing the transmission control signal with the output signal of the first comparator 304 and detecting whether or not a state corresponding to the transmission operation is detected, and comparing and inverting the operation control unit 360; Resistors 356-358 and 362-366 to the second direction A second comparator 308 for comparing and inverting the reflection detection voltage of the reflected power detecting means composed of the combiner 60 and the second detector 70 with the set reference voltage, the AND gate 368, the resistor 370, and the transistor. 372, a diode 374, and a relay 376. The alarm output unit 310 generates an alarm signal by logically combining the output signals of the detection controller 306 and the second comparator 308. .

Lines 201-204 in FIG. 3 are the same lines as lines 201-204 in FIG.

Hereinafter, an operation of an embodiment of the present invention will be described in detail with reference to FIGS. 2 and 3.

First, the transmission control signal generated from the control unit of the system is applied to the automatic output level control unit 40 and the alarm circuit 90 in FIG. 2 as logic "H" at the time of transmission and logic "L" at the time of no transmission. The logic state of the transmission control signal is one example.

If the high frequency amplifier 10 now operates normally, the high frequency signal amplified to a constant level is applied to the circulator 50 via the first directional coupler 20. Then, the small power induced by the impedance-matched first directional coupler 20 is converted into a voltage of a DC component as the first detector 30 so that the voltage divider of the automatic output level controller 40 and the alarm circuit 90 ( 302) separately supplied.

The voltage divider 302 lowers the voltage using the resistance value in a range in which the voltage divider resistors 312-316 have a minimum effect on the automatic output level control unit 40. The lowered voltage is composed of the resistors 320-322 and the operational amplifier 318 of the first comparator 304 and is amplified by being applied to a voltage amplifier having a constant gain.

The amplified voltage is applied to a comparison amplifier consisting of resistors 324-328 and an operational amplifier and compared with a reference voltage preset by resistors 326-328. The output signal of the first comparator 304 is applied to the exclusive oragate 336 to be exclusively ORed in the exclusive oragate 336 together with the transmission control signal applied from the controller of the system. In order to process this signal together with the reflected output signal, it is once again compared with an inverting amplifier composed of resistors 342-344 and 348-354 and an operational amplifier 346, and then an input terminal of the AND gate 368. To apply.

At this time, when there is no high frequency output signal reflected by the impedance matching between the load circuit and the output terminal of the high output amplifier, there is almost no high frequency signal output from the circulator 50 to the second directional coupler 60. The high frequency signal induced by the directional coupler 60 is nearly zero.

Therefore, the output voltage of the second detector 70 is close to the zero potential and is applied to the inverting input terminal (-) of the operational amplifier 360 of the second comparator 308 to be applied to the non-inverting input terminal (+) 356. And inverted by the reference voltage set in advance by -358, and applied to the other input terminal of the AND gate 368.

The AND gate 368 logically multiplies the alarm signal for detecting the former high frequency output signal level with the alarm signal for detecting the reflected high frequency output signal level to “on” the transistor 372 to drive the relay 376. By sending an alarm signal "H" indicating that the state of the high power amplifier is normal.

Contrary to the above, when the high frequency amplifier 10 operates abnormally, or when the output becomes below a certain level, or the magnitude of the reflected output signal due to impedance mismatch between the output terminal of the high output amplifier and the load circuit exceeds a certain level. When generated and detected, it operates in the opposite situation as described above, and sends an alarm signal "L" indicating that the state of the high power amplifier is abnormal to the control unit of the system to immediately stop using the high power amplifier.

Here, the alarm signal output from the alarm circuit 90 for each situation is generated as shown in the following table.

TABLE 1

In Table 1, when the alarm signal is logic "H", it indicates the normal operating state of the high output amplifier, and when logic "L", it indicates the abnormal operation state.

As described above, the present invention can reduce the output level loss of the high output amplifier to improve the actual efficiency and reliability, and at the same time, accurately monitor the output power level and the reflected power level of the high output amplifier to generate an alarm signal, thereby enabling accurate monitoring. There is this.

Claims (6)

A high frequency amplifier 10 for amplifying a high frequency signal for transmission, an output power detecting means for inducing and detecting an output signal of the high frequency amplifier 10, detecting and converting the detected output signal into a DC voltage, and the converted output detection voltage. In the high output amplifier provided with the automatic output level control part 40 which controls the supply power supply of the said high frequency amplifier 10 compared with a setting reference voltage, and maintains the level of output power constant, The said output power detection means has the automatic A voltage divider 302 for dividing the output detection voltage output to the output level control unit 40 by a constant voltage, a first comparator 304 for amplifying the divided output detection voltage and comparing it with a set reference voltage, and a transmission operation Corresponding to the presence or absence of a transmission control signal for controlling the driving of the high frequency amplifier 10 and the output signal of the first comparator 304 A detection control unit 306 for detecting and inverting the state corresponding to the new operation or not, and an alarm output unit for generating an alarm signal indicating the operation state of the high output amplifier by the output signal of the detection control unit 306. Surveillance alarm system characterized in that. A high frequency amplifier 10 for amplifying a high frequency signal for transmission, an output detecting means for inducing and detecting an output signal of the high frequency amplifier 10, detecting and converting the signal into a DC voltage, and setting the converted output detection voltage A high output amplifier having an automatic output level controller 40 for controlling a supply power of the high frequency amplifier 10 to maintain a constant level of output power compared to a reference voltage, wherein the output power detection means and the load circuit Reflection signal separation means for separating the reflection signal generated due to impedance mismatch, and detecting the detected reflection signal by detecting the detected reflection signal, converting the detected signal into a DC voltage, and the reflection power detection means. A pseudo load connected to consume the reflected signal and before output detection of the output power detecting means And an alarm circuit configured to detect an operating state of the high output amplifier and generate an alarm signal by comparing the voltage and the reflection detection voltage of the reflected power detection means with a corresponding reference voltage. The method of claim 2, wherein the alarm circuit detects the operation state of the high output amplifier by distinguishing the transmission time from the non-transmission time by the transmission control signal for controlling the driving of the high frequency amplifier 10 in response to the transmission operation. Surveillance alarm device, characterized in that. The monitoring alarm device according to claim 2, wherein the pseudo load is a resistance. The monitoring and warning device according to claim 2, wherein the reflected signal separation means is a three-terminal circulator. The voltage divider 302 of claim 2, wherein the alarm circuit divides the output detection voltage output from the output power detection means to the automatic output level control unit 40 by a constant voltage, and the divided output detection voltage. The first comparator 304 for amplifying and comparing the set reference voltage, and the transmission control signal for controlling the driving of the high frequency amplifier 10 and the output signal of the first comparator 304 in response to the presence or absence of a transmission operation. A detection control unit 306 which detects whether the state corresponds to the presence or absence of a transmission operation and compares and inverts the second control unit 308 which compares and inverts the reflection detection voltage of the reflected power detection unit with a set reference voltage; And an alarm output unit (310) for generating an alarm signal by ORing the output signals of the control unit (306) and the second comparator (308).