JP2001016145A - Frequency characteristics corrector for radio communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically correct frequency characteristics peculiar for equipment into desired frequency characteristics concerning radio communication equipment to utilize the frequency range of wide band. SOLUTION: This frequency characteristics corrector is provided with a transmission or reception circuit 10 or 20 for outputting a transmission or reception signal, variable equalizer circuits 13 and 23 for controlling the frequency characteristics of the transmission or reception signal, coupling circuits 14 and 24 connected to the output side of the variable equalizer circuits, band dividing filters 15A, 15B, 25A and 25B connected to the coupling circuits for dividing the frequency band of the transmission signal to the low frequency side and high frequency side of the equal band width, comparator circuits 17 and 27 for detecting and mutually comparing the power levels of respective bands and control circuits 18 and 28 for controlling the equalizer circuits on the basis of the compared result of the comparator circuits so as to provide the desired frequency characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frequency characteristic correcting device for a radio communication device, for example, a frequency characteristic correcting device for a transceiver used in microwave band communication such as satellite communication.

[0002]

2. Description of the Related Art In a radio transceiver having a wide operating frequency band, such as a satellite communication device, the frequency characteristic of the gain of the device within the operating frequency band increases, and as a result, the transmission level varies depending on the transmission frequency. Or the reception level changes depending on the reception frequency. In order to solve these problems, a variable equalizer circuit which is manually adjusted or a fixed equalizer circuit having a fixed correction characteristic is provided for each device. As another method, a circuit for correcting propagation path distortion of a received signal, that is, fading due to multipath generated in the propagation path, and shaping the reception spectrum on the reception side is provided.

[0003]

As described above, the conventional transceiver is provided with a variable equalizer circuit which is manually adjusted for each device or a fixed equalizer circuit having a fixed correction characteristic for each device. There are problems such as the necessity of adjustment, the inability to sufficiently obtain the desired frequency characteristics, and the need for a separate equalizer circuit for the frequency characteristics of externally connected devices or cables. Was. Further, with respect to a circuit for shaping the reception spectrum on the receiving side, which has been adopted as another method, the problem is that propagation path distortion, that is, fading due to the influence of multipath, occurs in a wide operating frequency band, for example, in a fixed satellite communication transceiver. In addition to the above, the correction of the frequency characteristics of transmission and reception of the entire apparatus cannot be performed. SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems. In particular, the present invention can reduce the frequency characteristics specific to a device in question and the frequency characteristics generated in an external connection device, a cable, or the like to a desired (usually flat). It is an object of the present invention to provide a frequency characteristic correction device capable of reducing the adjustment time by automatically correcting the frequency characteristic, and stabilizing the performance and reducing the production cost of the device.

[0004]

According to the present invention, there is provided a frequency characteristic correcting apparatus for a radio communication device, comprising: a transmitting or receiving circuit for outputting a transmitting or receiving signal; a variable equalizer circuit for controlling a frequency characteristic of the transmitting or receiving signal; A coupling circuit connected to the output side of the variable equalizer circuit, a band division filter connected to the coupling circuit and dividing the frequency band of the transmission signal into a low band side and a high band side having the same bandwidth, and a power of each band. A comparison circuit that detects the levels and compares them with each other, and controls a variable equalizer circuit based on the comparison result of the comparison circuit,
And a control circuit for obtaining a predetermined frequency characteristic.

[0005] A frequency characteristic correction apparatus for a radio communication device according to the present invention further comprises a transmission or reception circuit for outputting a transmission or reception signal, a variable equalizer circuit for controlling the frequency characteristics of the transmission or reception signal, and a variable equalizer circuit. A coupling circuit connected to the output side of the power supply, a band division filter connected to the coupling circuit and dividing the frequency band of the transmission signal into lower, middle, and higher bands having the same bandwidth; and power in each band. It comprises a comparison circuit for detecting the levels and comparing them with each other, and a control circuit for controlling a variable equalizer circuit based on the comparison result of the comparison circuit to obtain a predetermined frequency characteristic.

A frequency characteristic correction device for a radio communication device according to the present invention further comprises a transmission or reception circuit for outputting a transmission or reception signal, a variable equalizer circuit for controlling the frequency characteristics of the transmission or reception signal, and a variable equalizer circuit. A coupling circuit connected to the output side of the filter, a band division filter connected to the coupling circuit and dividing the frequency band of the transmission signal into a low band side and a high band side having the same bandwidth, and detecting a power level of each band. , A comparison circuit for comparing each with a predetermined reference value, and a control circuit for controlling the variable equalizer circuit based on the comparison result of the comparison circuit to obtain predetermined frequency characteristics.

A frequency characteristic correction device for a radio communication device according to the present invention further comprises a transmission or reception circuit for outputting a transmission or reception signal, a variable equalizer circuit for controlling the frequency characteristics of the transmission or reception signal, and a variable equalizer circuit. A coupling circuit connected to the output side of the power supply, a band division filter connected to the coupling circuit and dividing the frequency band of the transmission signal into lower, middle, and higher bands having the same bandwidth; and power in each band. It comprises a comparison circuit that detects the level and compares each with a predetermined reference value, and a control circuit that controls the variable equalizer circuit based on the comparison result of the comparison circuit to obtain a predetermined frequency characteristic. is there.

In the frequency characteristic correcting apparatus for a wireless communication device according to the present invention, the reference value may be a frequency of a cable for transmitting a signal transmitted from the coupling circuit or a signal to the receiving circuit and a frequency of an external connection circuit connected to the cable. It is set including the characteristics.

[0009] In the frequency characteristic correction apparatus for a wireless communication device according to the present invention, the control circuit may be configured such that a comparison circuit compares the control circuit.
Having a storage element for storing a signal when the level of each band matches or when the level of each band matches the reference value,
The variable equalizer circuit can be controlled by a signal stored in the storage element.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a transceiver according to Embodiment 1 of the present invention. In this figure, 10 is a transmitter, 20 is a receiver, 30 is an external connection device for transmitting and receiving signals to and from a radiating element such as an antenna (not shown), and 40 is a device for transmission from the transmitter 10 to the external connection device 30. A signal cable 50 is a signal cable for reception from the external connection device 30 to the receiver 20.

The transmitter 10 includes the following components. That is, reference numeral 11 denotes a transmission system circuit, which is connected to the transmission circuit 12 including the amplifier 12B, the attenuator 12C, the amplifier 12D, and the filter 12E connected to the signal input port 12A, the variable equalizer circuit 13, and the transmission signal cable 40. And a coupling circuit 14. Also, 1
Reference numerals 5A and 15B denote low-frequency band and high-frequency band division filters, which divide the entire frequency band used by the transmission system circuit 11 into equal frequency bandwidths within the used frequency band. 16A and 16B are power detectors for detecting the power level of each band division filter. Reference numeral 17 denotes a comparison circuit for comparing the output levels of the respective power detectors, and reference numeral 18 denotes a comparison circuit.
, That is, a control signal corresponding to the magnitude relationship between the low-frequency side and the high-frequency side is transmitted, whereby the variable equalizer circuit 1
3 is a control circuit for controlling the control signal 3 to obtain a desired frequency characteristic, for example, a flat frequency characteristic.
A.

The receiver 20 comprises the following components. That is, 21 is a receiving system circuit, which includes a filter 22E and an amplifier 22 connected to the receiving signal cable 50.
D, receiving circuit 22 including attenuator 22C and amplifier 22B
, A variable equalizer circuit 23, and a coupling circuit 24. 25A and 25B are band dividing filters on the low band side and the high band side, which divide the entire used frequency band of the receiving system circuit 21 with the same frequency bandwidth within the used frequency band. 26A and 26B are power detectors for detecting the power level of each band division filter. 2
Reference numeral 7 denotes a comparison circuit for comparing the output levels of the power detectors with each other. Reference numeral 28 denotes a control signal corresponding to the comparison result of the comparison circuit 27, that is, a control signal corresponding to the magnitude relationship between the low frequency side and the high frequency side. The control circuit controls the circuit 23 to obtain a desired frequency characteristic, for example, a flat frequency characteristic, and has a storage element 28A for storing a control signal. The comparison circuits 17 and 27 and the control circuits 18 and 28 of the transmitter 10 and the receiver 20 and the storage elements 18A and 28 included therein are included.
A can use a common circuit.

Next, the operation of the first embodiment will be described. Regarding the transmitter 10, the signal input to the transmission circuit 12 from the signal input port 12A is such that the amplifiers 12B and 12D, the attenuator 12C, and the filter included therein when the control signal is not input to the variable equalizer circuit 13. After being amplified, attenuated, and filtered by 12E or the like, the transmission system circuit 11 passes through the coupling circuit 14 in a state where the transmission system circuit has frequency characteristics due to the inherent frequency characteristics and variations in these devices and transmission lines. Output from When the external connection device 30 is provided, the signal output from the transmission system circuit 11 is transmitted to the transmission signal cable 4.
The signal is supplied to the external connection device 30 through the external device 0, and is transmitted to the outside from a radiation element such as an antenna (not shown). At this time, a signal having a certain frequency characteristic is transmitted in a state where the frequency characteristics of the transmission signal cable 40 and the external connection device 30 are added in addition to the frequency characteristic of the transmission system circuit 11.

At the time of signal transmission from the transmission system circuit 11, a part of the transmission signal is taken out by the coupling circuit 14 and divided into the low band side and the high band side by the band division filters 15A and 15B. Furthermore, the voltage obtained by detecting the power level of each band division filter by the power detectors 16A and 16B and comparing the respective outputs with each other by the comparison circuit 17 is
The control circuit 18 converts the signal into a control signal for the variable equalizer circuit 13 and controls the variable equalizer circuit 13 to obtain a desired frequency characteristic.

FIG. 2 is a schematic diagram for explaining the situation of frequency characteristic correction by the control signal. In this figure, the horizontal axis represents frequency, and the vertical axis represents voltage. Further, 61 is an example of the frequency characteristic before correction, 71 is an example of the frequency characteristic of the variable equalizer circuit, and 81 is an example of the frequency characteristic after correction. When the comparison result of the comparison circuit 17 is that the detection voltage on the low frequency side is smaller than the detection voltage on the high frequency side as shown at 61, the variable equalizer circuit 13 is switched to the low frequency side as shown at 71. Control is performed so that the voltage is higher than the high-frequency side voltage. When the detection voltage is opposite, the control is also performed in the opposite direction. Such control is repeated until the voltages of the two become equal, and when both become equal, the control is stopped and the control values are stored in the storage element 18A. After that, the coupling circuit 1
4 and the comparison circuit 17 are separated, and the variable equalizer circuit 13 is controlled only by the control value stored in the storage element 18A, whereby a desired frequency characteristic which is initially set can be obtained.

Next, the operation of the receiver 20 will be described. When the external connection device 30 is provided, a signal input from the outside to a radiating element such as an antenna (not shown) passes through the external connection device 30 and is transmitted to the reception circuit 22 via the reception signal cable 50 connected thereto. Is entered. Receiving circuit 2
2 is input to a filter 22 included therein.
E, which are filtered, amplified, and attenuated by the amplifiers 22D and 22B, the attenuator 22C, and the like, and the frequency characteristics of the external connection device 30 and the reception signal cable 50 due to the frequency characteristics and variations inherent to these devices and transmission lines. In addition, the entire reception system circuit has a frequency characteristic. When no control signal is input to the variable equalizer circuit 23, the signal is output from the receiving circuit 21 via the coupling circuit 24 in the above state.

When a reception signal is output from the reception system circuit 21,
A part of the received signal is taken out by the coupling circuit 24, and divided into the low band side and the high band side by the band division filters 25A and 25B.
Further, the power level of each band division filter is determined by the power detector 2.
6A and 26B, and each output is compared with the comparison circuit 2
7, the voltage obtained by the mutual comparison is converted into a control signal by the control circuit 28 and the variable equalizer circuit 23 is controlled. These operations are performed in the case of the above-described transmitter. The description is omitted because it is the same as.

Embodiment 2 FIG. Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 3 shows the second embodiment.
FIG. 2 is a block diagram showing a configuration of a transceiver according to the first embodiment. In this figure, the same or corresponding parts as those in FIG. The difference from FIG. 1 is that three band splitting filters (15A to 15C, 25
A to 25C), and the lower side having the same frequency bandwidth,
It is divided into a middle band and a high band, and three power detectors (16A to 16C, 26A to 26
C).

Each of the power detectors 16A to 16C or 26A
The power level of each band detected by .about.26C is compared with the comparison circuit 17 in the transmitter 10 and the comparison circuit 2 in the receiver 20.
7, and the obtained voltage is compared with the transmitter 10
In the control circuit 18 and the receiver 20, the control circuit 28 converts the control voltage into control voltages for the respective variable equalizer circuits 13 and 23 and controls the variable equalizer circuits 13 and 23 to obtain desired frequency characteristics. .

FIG. 4 is a schematic diagram for explaining the situation of frequency characteristic correction by the control signal. In this figure, the horizontal axis represents frequency, and the vertical axis represents voltage. 62 is an example of the frequency characteristic before correction, 72 is an example of the frequency characteristic of the variable equalizer circuit, and 82 is an example of the frequency characteristic after correction. As shown by 62 in the comparison result of the comparison circuits 17 and 27, the detection voltage on the low frequency side is the smallest, the detection voltage on the middle frequency side is the largest, and the detection voltage on the high frequency side takes a value between the two. In this case, as shown by 72, the variable equalizer circuits 13 and 23 are set so that the power in the low band is the largest, the power in the middle band is the smallest, and the power in the high band is a value between the two. To control. Such a control is repeated until the voltages of the three become equal, and when the three become equal, the control is stopped, and
The control values at that time are stored in the storage elements 18A and 28A,
Thereafter, similarly to the case of FIG. 1, the desired frequency characteristics are obtained by controlling the variable equalizer circuits 13 and 23 according to the stored values.

Embodiment 3 Next, a third embodiment of the present invention will be described with reference to the drawings. FIG. 5 shows the third embodiment.
FIG. 2 is a block diagram showing a configuration of a transceiver according to the first embodiment. In this figure, the same or corresponding parts as those in FIG. The difference from FIG.
The reference values 19 and 29 are set to 7, 27, respectively, and each power detector 1
The point is that the outputs of 6A, 16B, 26A, and 26B are compared with reference values.

Each of the power detectors 16A, 16B, 26A, 2
The power levels on the low band side and the high band side detected by 6B are compared with reference values 19 and 29 preset by a comparison circuit 17 in the transmitter 10 and a comparison circuit 27 in the receiver 20, respectively. Control circuit 1
By converting the control voltages into control voltages for the variable equalizer circuits 13 and 23 at 8 and 28 and controlling the variable equalizer circuits 13 and 23, desired frequency characteristics are obtained.
That is, in the above-described first and second embodiments, the frequency characteristic correction is performed by the mutual comparison of the band-divided detection voltages, but is performed by comparing each detection voltage with the reference voltage. It is possible to correct the absolute value.

FIG. 6 is a schematic diagram for explaining the situation of correction of the frequency characteristic by the control signal. In this figure, the horizontal axis represents frequency, and the vertical axis represents voltage. Further, 63 is an example of the frequency characteristic before correction, 73 is an example of the frequency characteristic of the variable equalizer circuit, and 83 is an example of the frequency characteristic after correction. When the comparison results of the comparison circuits 17 and 27 become as shown in 63 or 73, control voltages corresponding to the respective magnitudes are applied so that each detection voltage becomes equal to the reference value. Control. Such control is repeated until each detection voltage becomes equal to the reference value, and control is stopped when each detection voltage becomes equal to the reference value, and the control value at that time is stored in the storage elements 18A and 28A. Thereafter, similarly to the case of FIG. 1, the desired frequency characteristics are obtained by controlling the variable equalizer circuits 13 and 23 according to the stored values. Note that FIG.
Although the reference values 19 and 29 are set in the comparison circuit of FIG. 3, the same operation and effect can be expected by setting the reference values in the comparison circuit of FIG.

Embodiment 4 Next, a fourth embodiment of the present invention will be described with reference to the drawings. This embodiment is characterized in that reference values 19 and 29 are corrected by providing a correction input port indicated by 19A in the transmitter 10 of FIG. 5 and a correction input port indicated by 29A in the receiver 20. I do. That is, in the third embodiment, when the external connection device 30 or the transmission or reception signal cables 40 and 50 are connected, desired characteristics can be obtained in the total frequency characteristics including the frequency characteristics of their gains. Therefore, a signal corresponding to the total frequency characteristic is given from the correction input ports 19A and 29A, and the reference values 19 and 29 of the comparison circuits 17 and 27 are respectively corrected, and the corrected reference value is used as the reference value in the third embodiment. It is something to do.

[0025]

Since the frequency characteristic correcting apparatus for a radio communication device according to the present invention is configured as described above, there is a problem that the transmission level changes depending on the transmission frequency or the reception level changes depending on the reception frequency. Can automatically correct the frequency characteristics of a device that had a problem to the desired frequency characteristics without manually adjusting each device or using a separate equalizer circuit for externally connected devices, cables, etc. In particular, in a wireless communication device using a wide band frequency range, adjustment for variation in frequency characteristics of each device can be automated, and the adjustment time can be reduced. Further, since the overall frequency characteristics including the external connection device, the cable, and the like can be corrected, the performance can be stabilized and the production cost of the device can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a transceiver according to Embodiment 1 of the present invention.

FIG. 2 is a schematic diagram for explaining a situation of correction of a frequency characteristic according to the first embodiment.

FIG. 3 is a block diagram showing a configuration of a transceiver according to a second embodiment of the present invention.

FIG. 4 is a schematic diagram for explaining a state of correction of a frequency characteristic according to the second embodiment.

FIG. 5 is a block diagram showing a configuration of a transceiver according to Embodiments 3 and 4 of the present invention.

FIG. 6 is a schematic diagram for explaining a situation of correction of frequency characteristics according to the third and fourth embodiments.

[Explanation of symbols]

Reference Signs List 10 transmitter, 11 transmission circuit, 12 transmission circuit, 13 variable equalizer circuit, 14 coupling circuit, 15A, 15B band division filter, 16A,
16B power detector, 17 comparison circuit, 18 control circuit, 18A storage element, 20 receiver, 21
Receiving system circuit, 22 receiving circuit, 23 variable equalizer circuit, 24 coupling circuit, 25A, 25B band division filter, 26A, 26B power detector, 27
Comparison circuit, 28 control circuit, 28A storage element, 30 external connection device, 40, 50 signal cable.

Claims (6)

[Claims] A transmission or reception circuit for outputting a transmission or reception signal; a variable equalizer circuit for controlling a frequency characteristic of the transmission or reception signal; a coupling circuit connected to an output side of the variable equalizer circuit; A band division filter connected to the coupling circuit, for dividing the frequency band of the transmission signal into a low band side and a high band side having the same bandwidth, a comparison circuit for detecting a power level of each band and comparing them with each other; And a control circuit for controlling the variable equalizer circuit based on the comparison result to obtain a predetermined frequency characteristic. 2. A transmission or reception circuit for outputting a transmission or reception signal, a variable equalizer circuit for controlling a frequency characteristic of the transmission or reception signal, a coupling circuit connected to an output side of the variable equalizer circuit, A band division filter that is connected to the coupling circuit and divides the frequency band of the transmission signal into low-band, middle-band, and high-band sides having equal bandwidths;
A wireless communication system comprising: a comparison circuit that detects power levels of respective bands and compares them with each other; and a control circuit that controls the variable equalizer circuit based on a comparison result of the comparison circuit to obtain a predetermined frequency characteristic. Machine frequency response correction device. 3. A transmission or reception circuit for outputting a transmission or reception signal, a variable equalizer circuit for controlling a frequency characteristic of the transmission or reception signal, a coupling circuit connected to an output side of the variable equalizer circuit, A band division filter that is connected to a coupling circuit and divides a frequency band of a transmission signal into a low band side and a high band side having the same bandwidth, and a comparison that detects a power level of each band and compares each with a predetermined reference value. A frequency characteristic correction device for a wireless communication device, comprising: a circuit; and a control circuit that controls the variable equalizer circuit based on a comparison result of the comparison circuit to obtain a predetermined frequency characteristic. 4. A transmission or reception circuit for outputting a transmission or reception signal, a variable equalizer circuit for controlling frequency characteristics of the transmission or reception signal, a coupling circuit connected to an output side of the variable equalizer circuit, A band division filter that is connected to the coupling circuit and divides the frequency band of the transmission signal into low-band, middle-band, and high-band sides having equal bandwidths;
A comparison circuit that detects the power level of each band and compares each with a predetermined reference value, and a control circuit that controls the variable equalizer circuit based on the comparison result of the comparison circuit to obtain a predetermined frequency characteristic A frequency characteristic correction device for a wireless communication device comprising: 5. The reference value is set including frequency characteristics of a cable for transmitting a transmission signal from a coupling circuit or a signal to a reception circuit and an external connection circuit connected to the cable. The frequency characteristic correction device for a wireless communication device according to claim 3. 6. The control circuit has a storage element for storing a signal when the level of each band coincides or when the level of each band coincides with a reference value by comparing the comparison circuit. The variable equalizer circuit can be controlled by the stored signal.
The frequency characteristic correction device for a wireless communication device according to claim 4.