JP2005045715A - Amplifier - Google Patents

Abstract

An object of the present invention is to unify a plurality of detectors used in an amplifying apparatus and to reduce the size and cost of the amplifying apparatus.
An amplifier 401 of an amplifying device, an input level detection coupler 402 provided before the amplifier, an output level detection coupler 404 provided after the amplifier, the input level detection coupler, and the output A detector 103 for detecting the level of the level detection coupler, and one of terminals connected to either the output detection coupler or the input detection coupler, and the other terminal connected to the detector. An amplifying apparatus including a unit 101 and an isolator 102 provided between the input level detection coupler and the switching unit.
[Selection] Figure 1

Description

  The present invention relates to a high-frequency amplifier used in, for example, a base station and a repeater of a wireless system.

  In recent years, systems using radio have been very popular as represented by mobile phones. And from the utilization form, infrastructure equipment is required to have high reliability, low cost, and small size.

FIG. 4 shows one form of a conventional amplifying apparatus, which is used for a so-called relay amplifying apparatus or a base station. A conventional amplifying apparatus will be described below.
Reference numeral 401 denotes an amplifier that amplifies a high frequency. Reference numeral 402 denotes an input level detection coupler that extracts a high frequency input level. Reference numeral 3 denotes a first detector that detects the voltage of a signal output from the input level detection coupler 402. Reference numeral 404 denotes an output level detection coupler that extracts the output from the amplifier, that is, the voltage of the amplified signal, and reference numeral 405 denotes a second detector that detects the level of the signal output from the output level detection coupler 404.
Further, 406 is an A / D converter that outputs the voltage detected by the first and second detectors as digital data so that it can be read by the microcomputer, 407 is a control unit for controlling the respective components, and 408 is for control. 409 is a memory for storing each setting value, 409 is a D / A converter that outputs an adjustment value for adjusting the variable attenuator 410 that adjusts the gain of a signal input to the amplifier, and 411 is a current temperature. It is a temperature detection part for detecting.

The gain of the amplifier 401 may change depending on the surrounding environment, particularly the temperature. On the other hand, since the gain must be fixed, such a change in gain must be corrected in some form. As a means for that, it is necessary to detect the high frequency level of the input / output and to control the variable attenuator 410 so that the difference between the high frequency level of the input / output becomes constant, thereby maintaining a constant gain. However, as can be seen from FIG. 5 showing the characteristics of the detector, the characteristics of the detector vary depending on the temperature, and the characteristics of the individual detectors also vary. It is necessary to set a value for correcting the variation of the detector from the temperature and the input level, write it in the memory 408, read the ambient temperature by the temperature detector 411 during operation, and correct the variation of the detector.

Next, a flowchart of the amplifying apparatus in FIG. 4 will be described.
The input level is read by the input level detection coupler 402 and the first detector 403, and further the output level is read by the output level detection coupler 404 and the second detector 405 (S61). Subsequently, the ambient temperature is read by the temperature detector 411 (S63). The input / output level detection voltage is corrected from the detected temperature value (S64), the input / output level is compared to determine the gain level (S65), and if the gain is high, the variable attenuator 410 is set to decrease the gain (S66). If it is determined that the gain is low, setting is made to raise the variable attenuator 410 (S67).

  The comparison of the input / output gains of the amplifiers described so far is described in Patent Document 1, for example. FIG. 7 of Patent Document 1 discloses a technique for detecting input / output of an amplifier, comparing gains, and confirming whether the amplifier is normally amplified as described in the section of the prior art of this application. ing.

  Further, FIG. 1 of Patent Document 1 discloses a configuration in which the number of detectors is reduced by improving FIG. 7 of Patent Document 1. This discloses a technique for detecting by switching the output from the input level detection coupler and the output from the output level detection coupler by a switch.

Next, another amplification device will be described with reference to 7. FIG. 7 shows a distortion compensation amplifying apparatus called a feedforward amplifying apparatus, which has a configuration including the amplifier of FIG. 4, for example. Here, the operation of the feedforward amplification device (hereinafter referred to as FF amplification device) will be described. In FIG. 7, 701 is an input terminal, 702 is a level detector, 703 is a directional coupler, 704 is a vector adjuster, 705 is a main amplifier, 706 is a delay line, and 707 is a directional coupler. From the directional coupler 703 to the directional coupler 707 downstream of the main amplifier 705 is referred to as a distortion detection loop.

In the figure, reference numeral 708 is a delay line, 709 is a vector adjuster, 710 is an auxiliary amplifier, 711 is an output side directional coupler, and 712 is an output terminal, and the directional coupler 707 to the output side directional coupler 711. This is called a distortion removal loop. Reference numeral 713 denotes a pilot signal generator, 714 denotes a level detector, 715 denotes a pilot signal level detector, 716 denotes an output level detector, 717 denotes a control circuit, and 718 denotes a circulator. The control circuit 717 includes a control unit that controls the entire apparatus and a storage unit that stores programs and data for control.

The input signal a of a plurality of channels input to the input terminal 701 is distributed into two signals b and c by the input side directional coupler 703. One of the signals b is amplified by the main amplifier 705 via the vector adjuster 704. At this time, intermodulation distortion occurs due to the nonlinear characteristic of the main amplifier 705. A signal including this distortion is input to the directional coupler 707 in reverse phase. On the other hand, the signal c flowing through the delay line 706 is input to the directional coupler 707 after being delayed for the same time as the delay time of the path of the signal b without distortion. The directional coupler 707 suppresses the transmission input signal by setting the degree of coupling, and outputs only the distortion component as one output e. The other output d passing through the delay line 708 is a main signal including a distortion component amplified by the main amplifier 705.

A distortion component signal e output from the directional coupler 707 is amplified by an auxiliary amplifier 710 (also referred to as an error amplifier) through a vector adjuster 709. This amplification degree is set so as to be the same level as the distortion component of the main signal d including distortion output from the other terminal of the directional coupler 707, and is reversed in phase to the output side directional coupler 711. Entered. On the other hand, the main signal d is input to the output side directional coupler 711 after being delayed by the delay line 708 for the same time as the delay time of the path of the distortion component signal e. In the output-side directional coupler 711, the main signal d and the antiphase signal amplified by the auxiliary amplifier 710 are added to output a transmission output signal g without distortion in which distortion components are canceled. In this way, intermodulation distortion generated when the transmission input signal a is amplified by the main amplifier 705 is compensated.

The vector adjusters 704 and 709 are parts that are controlled by the control circuit 717 to adjust the attenuation amount and the phase shift amount in order to optimize the distortion compensation operation.

The gain monitoring of the FF amplifier is performed by the level of the transmission input signal a detected by the level detector 702 provided at the input terminal 701 and the pilot level detector 15 provided at the output terminal 712. The control circuit 717 compares the data at the output of the pilot level detector 715 and the output level detector 716 that detects the level of the output signal g, and calculates the gain.

JP 2002-252564 A

However, in the case of using the amplification device as shown in FIG. 4 or FIG. 7, it is necessary to correct by performing a temperature test on all the devices in order to absorb the variation of the components themselves, and to correct the variation of the detector, There is a problem in that the number of man-hours for production increases because each unit is corrected while observing the temperature characteristics.

In addition to the above problems, there are problems that the more items to be detected, the greater the number of detectors, the larger the entire apparatus, and the higher the cost.

The present invention solves the above-mentioned problems, and reduces the number of production steps by reducing the number of detectors having variations from the items to be detected, for example, to one, reducing the size and cost of the apparatus. It aims to make it easier.

  In order to solve the above problems in the present invention, an amplifier, an input level detection coupler provided in the previous stage of the amplifier, an output level detection coupler provided in the subsequent stage of the amplifier, and the input level detection coupler, A detector for detecting the level of the output level detection coupler, one of the terminals is connected to either the output detection coupler or the input detection coupler, and the other terminal is connected to the detector. Provided is an amplifying device including a switching unit and an isolator provided between the input level detection coupler and the switching unit.

  Further, a plurality of demultiplexing units for demultiplexing an input signal and the like, a detection unit for detecting a signal level from the demultiplexing unit, provided between the detection unit and the plurality of demultiplexing units, one of the terminals is Provided is an amplifying apparatus that is connected to one of the demultiplexing units and the other terminal is composed of a switching unit connected to the detection unit and a control unit that controls the switching unit.

As a result, for example, in order to correct variations in detectors, the number of production man-hours has increased because all of the conventional devices are corrected while observing the temperature characteristics. There is an effect that man-hours can be reduced.

Since individual correction due to variations in detectors is reduced, stable characteristics can be obtained. Moreover, since it is not necessary to use the power used for each detector, the power consumption can be reduced.

Furthermore, there are problems that the more items to be detected, the greater the number of detectors, the larger the entire apparatus, and the higher the cost. However, the number of detectors is reduced by applying the present invention. Since the temperature IC is deleted, it is possible to reduce the size of the entire apparatus and reduce the cost.

Next, examples will be described. The first embodiment is an improvement of the amplifying apparatus of FIG. 4, and the second embodiment is an improvement of the amplifying apparatus of FIG.

Example 1 will be described with reference to FIG.
FIG. 1 is different from the configuration of FIG. 4 in that a high frequency relay is provided, a single detector is provided, an isolator is provided, and a temperature detector is omitted. In addition, since what has the same number as FIG. 4 is the structure similar to FIG. 4, description is abbreviate | omitted here.
Reference numeral 101 denotes a high frequency relay, and reference numeral 102 denotes an isolator provided between the input level detection coupler 402 and the high frequency relay 101. The high frequency relay 101 is switched to the input signal side of the amplification device 401 and the output signal side from the amplification device 401. For example, there is a high frequency relay using a semiconductor.
The isolator 102 is for preventing the high frequency on the output side from oscillating by being coupled to the high frequency input side via the high frequency relay 101. Although an isolator is used here, the present invention is not limited to this. Any isolator may be used as long as it prevents the high frequency on the output side from being coupled to the input side via the high frequency relay.
Furthermore, it has a detector 103 capable of detecting the level of the input signal and output signal to the amplifier.

Next, the operation will be described with reference to FIG.
When the input signal is input, the high frequency relay 101 is switched to the input side (S22). The input signal is received by the input level detection coupler 402, and further detected by the detector 103 to acquire the input level (S23). After the input level is acquired, the high frequency relay 101 is switched to the output side (S24). Here, the output signal is taken in by the output level detection coupler 404, and further detected by the detector 103 to obtain the output level (S25). Here, the control unit 407 compares the level of the input signal with the level of the output signal, and confirms the gain (S26). If the gain is higher than normal, the variable attenuator 410 is set to decrease the gain (S27), and if the gain is not higher than normal, the variable attenuator is set to increase the gain (S28). Here, the case where the gain is normal is not described, but in this case, the variable attenuator is not adjusted.

As a result, if the power entering the detector is the same, the difference between the input side detection voltage and the output side detection voltage is the same even if there is a difference in the absolute value of the voltage after detection. Thus, the variable attenuator can be controlled, and the gain can be maintained without fail even if the temperature is variable.

Next, a second embodiment will be described with reference to FIG.
The second embodiment is an application of the amplification device of FIG. FIG. 7 is a diagram in which the input level detector 702, the level detector 714, the pilot signal level detector 715, and the output level detector 716 of the conventional FF amplifier of FIG. 7 are combined into one detector.

In the description of FIG. 3, the same reference numerals as those in FIG. Reference numeral 301 denotes a switch, and 302 denotes a detector.
One terminal of the switch 301 is connected between the input terminal 701 and the directional coupler 703, between the directional coupler 707 and the vector adjuster 709, and between the directional coupler 711 and the output terminal 712. ing. The other is connected to the detection circuit 302.

Here, the input signal level, the distortion level after amplification, the distortion level after distortion compensation, and the output level are detected in order.
As for the input signal level, one terminal connected between the input terminal 701 and the directional coupler 703 is connected to the other terminal connected to the detection circuit 302, and the input of the input signal a is detected by the detection circuit 302. The level is detected, and then the output of the detection circuit 302 is read by the control circuit 717.
The amplified distortion level is obtained by connecting one terminal connected between the directional coupler 707 and the vector adjuster 709 and the other terminal connected to the detection circuit 302, and amplifying the distortion level by the detection circuit 302. The distortion level of the distortion component e is detected, and then the output of the detection circuit 302 is read by the control circuit 717.
In the case of the output level, one terminal connected between the directional coupler 711 and the output terminal 712 and the other terminal connected to the detection circuit 302 are connected, and the detection circuit 302 uses the directional coupler. The signal level of the output signal g from 711 is detected, and then the output of the detection circuit 302 is read by the control circuit 717.
The distortion level after distortion compensation is detected by connecting one terminal connected to the circulator 718 provided between the directional coupler 711 and the output terminal 712 and the other terminal connected to the detection circuit 302. The level of the pilot signal of the output signal g of the directional coupler 711 is detected by the circuit 302, and then the output of the detection circuit 302 is read by the control circuit 717.
Based on these read values, the control circuit 717 monitors the entire apparatus.
Although the detection circuit is a diode in FIG. 7, it is not limited to this, and any circuit can be used as long as it can detect the level of each signal.

  When changing the monitoring point between the input terminal and the directional coupler 703, between the directional coupler 707 and the vector adjuster 709, between the directional coupler 711 and the output terminal 712, etc., first, the control circuit A switching signal is output from 717 to the switching device 301 to change the connection state of the switching device 301. These changes are made in a time-sharing manner.

Here, various signals may be used as a signal to be amplified by the amplifier, and for example, a signal to be transmitted by radio may be used.
Various amplifiers may be used. For example, an amplifier composed of one amplifying element may be used, or a plurality of amplifying elements may be combined. May be used.

  In addition, as the magnitude of a signal to be detected such as an input signal or a distortion component, various magnitudes may be detected. For example, the magnitude of a level such as power can be detected.

  Note that the method of distortion compensation performed by the amplifying apparatus is not necessarily limited to the feed forward method, and other methods may be used. As an example, an adaptive predistortion method (APD method) or a digital predistortion method (DPD method) can be used as a distortion compensation method. In this case, the present invention includes a plurality of detectors of these distortion compensation amplification devices. The configuration of the first embodiment can be applied before and after the amplifiers used in the amplifiers.

Moreover, the amplification device according to the present invention can be applied to, for example, a base station device or a relay amplification device provided in a wireless communication system such as a mobile communication system.
Here, as the wireless communication system, for example, various systems such as a mobile phone system and a simple mobile phone system (PHS: Personal Handy phone System) may be used.
In addition, as a communication method, there are various methods such as a CDMA (Code Division Multiple Access) method, a W (Wide band) -CDMA method, a TDMA (Time Division Multiple Access) method, and an FDMA (Frequency Division Multiple Access) method. May be used.

Here, the configuration of the amplification device and the like according to the present invention is not necessarily limited to the above-described configuration, and various configurations may be used. The present invention can also be provided as, for example, a method or method for executing processing according to the present invention, a program for realizing such a method or method, and the like.
The application field of the present invention is not necessarily limited to the above-described fields, and the present invention can be applied to various fields.

In addition, as various kinds of processing performed in the amplifying apparatus according to the present invention, for example, control is performed by executing a control program stored in a ROM (Read Only Memory) in a hardware resource including a processor, a memory, and the like. For example, each functional unit for executing the processing may be configured as an independent hardware circuit.
In addition, the present invention can be grasped as a computer-readable recording medium such as a floppy (registered trademark) disk or a CD (Compact Disk) -ROM storing the control program, or the program (itself). The processing according to the present invention can be performed by inputting a program from a recording medium to a computer and causing the processor to execute the program.

First embodiment of the present invention Flowchart of the first embodiment of the present invention Second embodiment of the present invention Conventional amplifier Detector characteristics Flowchart of a conventional amplification device Conventional amplifier

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 ... High frequency relay 102 ... Isolator 103 ... Detector 301 ... Switcher 302 ... Detector 401 ... Amplifier 410 ... Attenuator 705 ... Main amplifier 709 ... Sub-amplifier 717 ... Control circuit

Claims (3)

An amplifier, an input level detection coupler provided in the previous stage of the amplifier, an output level detection coupler provided in the subsequent stage of the amplifier, and a detection for detecting the levels of the input level detection coupler and the output level detection coupler And one of the terminals is connected to either the output detection coupler or the input detection coupler, and the other terminal is connected to the detector, the input level detection coupler, An amplifying device comprising an isolator provided between the switching unit. The attenuator for adjusting the gain of the amplifier provided between the input level detection coupler and the amplifier, and a controller for adjusting the attenuator according to the output of the detector. 2. The amplifier according to 2. Provided between a plurality of demultiplexing units for demultiplexing an input signal and the like, a detection unit for detecting a signal level from the demultiplexing unit, between the detection unit and the plurality of demultiplexing units, and one of the terminals is any An amplifier comprising: a switching unit connected to the demultiplexing unit, and a second terminal connected to the detection unit; and a control unit for controlling the switching unit.

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