JP3388460B2 - Transmission output control circuit and wireless device using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission output control circuit and a wireless device using the same, and more particularly to AGC (Au
The present invention relates to a transmission output control circuit that controls a transmission output to a constant level by a to gain control circuit and a wireless device using the transmission output control circuit.

[0002]

2. Description of the Related Art Conventionally, in a transmission output control circuit provided in a radio device, a weak high frequency signal is amplified,
It is required to keep the transmission output at a constant value regardless of the usage environment or usage form.

Therefore, as the transmission output control circuit, an AGC circuit which automatically controls the transmission output to a constant value is widely used.

FIG. 3 is a diagram showing a conventional transmission output control circuit using an AGC circuit.

In this conventional example, as shown in FIG. 3, a gain (Variable Gain Amplifier) 30 that changes a gain according to a control voltage, amplifies an input signal by the gain, and outputs the amplified signal, and a VGA 30. An amplitude detector 31 for detecting and outputting the amplitude level of the signal output from the VGA 3
The memory 33 in which the correction data of the control voltage for changing the gain at 0 is stored, and the amplitude level of the signal output from the VGA 30 are stored in the memory 33 so that the amplitude level becomes the value instructed by the external setting signal. A VGA control circuit 32 that outputs a control voltage for changing the gain of the VGA 30 based on the correction data and the amplitude level detected by the amplitude detector 31.

In the transmission output control circuit configured as described above, the input signal is amplified by the VGA 30 with a predetermined gain and output through the output terminal. At this time, the amplitude detector 31 detects the amplitude level of the signal output from the VGA 30 and outputs it to the VGA control circuit 32. In the VGA control circuit 32, VGA3
Based on the correction data stored in the memory 33 and the amplitude level detected by the amplitude detector 31, the optimum amplitude level of the signal output from 0 becomes the value instructed by the external setting signal. The control voltage is calculated and VGA30
Is output to. Then, in VGA30, V
The gain changes based on the control voltage output from the GA control circuit 32, and the input signal is amplified by the gain and output via the output terminal.

The operation of the transmission output control circuit configured as described above will be described below in more detail with reference to the drawings.

FIG. 4 is a diagram showing operating characteristics of the control voltage and the amplitude level of the output signal in the VGA 30 shown in FIG.

In FIG. 4, a graph line 41 shows the operating characteristics when operated under standard environmental conditions and frequency conditions, and the operating environment changes from the above-mentioned standard conditions.
The graph line 42 shows the operating characteristics when the operating characteristics change.

As shown in FIG. 4, there is a linear relationship between the control voltage and the amplitude level. The amplitude level can be lowered by increasing the control voltage, and the amplitude level can be increased by lowering the control voltage. it can. Further, the operating characteristics of the control voltage and the amplitude level vary depending on the usage environment, usage frequency, and the like.

Here, the VGA control circuit 32 (see FIG. 3)
When the set value of the amplitude level instructed by the external setting signal input to P is P1, under the reference condition, the graph line 4
The control voltage output from the VGA control circuit 32 is V1, and the gain of the VGA 30 changes according to the control voltage V1. After that, if the operating environment changes and the operating characteristics fluctuate as shown by the graph line 42, V
If the control voltage input to the GA 30 remains V1, the amplitude level increases to P2 and exceeds the set value. Therefore, in the VGA control circuit 32, the control voltage is controlled to V2 based on the amplitude level detected by the amplitude detector 31 and the correction data stored in the memory 33, whereby the VGA 30 outputs the control voltage. The amplitude level of the signal is always controlled to P1.

[0012]

However, in the conventional transmission output control circuit as described above, the operating characteristic of the control voltage and the amplitude level is in the state of the graph line 42, and the amplitude level is temporarily changed by the external setting signal. When the mute setting is set to OFF (output cutoff), the VGA control circuit 32 recognizes that the operation characteristics are those under the reference condition after the mute setting is released, and the control voltage V1 is output. Therefore, there is a problem in that the amplitude level after the mute setting is released instantaneously increases to P2, causing interference with an adjacent circuit.

In order to solve the above-mentioned problems, a method of gradually increasing the amplitude level from the minimum value to the set value after canceling the mute setting has been devised, but in this method, after canceling the mute setting, There is a problem that it takes time until a predetermined output is obtained.

The present invention has been made in view of the problems of the above-described conventional technique, and suppresses an increase in the transmission output after the mute setting is released, regardless of the use condition and the use form, and shortens the output. An object is to provide a transmission output control circuit that can obtain a predetermined output in time.

[0015]

In order to achieve the above object, a radio apparatus according to the present invention comprises a variable gain amplifying means for changing a gain according to a control voltage and amplifying and outputting a transmission signal by the gain. A transmission output detection means for detecting the level of the transmission output output from the variable gain amplification means, a first storage means for storing a correction value of a control voltage applied to the variable gain amplification means, and an external setting When a signal is input and the mute state is set by the external setting signal, a control voltage is generated so that the level of the transmission output becomes the mute state, and when the external setting signal sets the operating state, the control voltage is generated. The gain in the variable gain amplification means is changed based on the level of the transmission output detected by the transmission output detection means and the correction value of the control voltage stored in the first storage means. And a second storage means for storing the control voltage output from the gain control means when the mute is set. A wireless device having two transmitting devices provided with a transmission output control circuit in parallel, wherein the gain control means sets the control voltage when the mute state is released after the mute state is set. The control voltage stored in the second storage means is used when the mute is set, and when one of the two transmitters is set to the operating state, the other transmitter is set to the mute state. It is characterized by being done.

[0016]

[0017]

[0018]

Further, when the operation of the transmitting device in the operating state is stopped, the transmitting device in the mute state becomes the operating state.

Further, the present invention is characterized by having a combiner for combining and outputting the signals output from the two transmitters.

(Operation) In the present invention configured as described above, the control voltage for changing the gain in the variable gain amplifying means generated by the gain controlling means is the second control voltage.
When the mute setting is performed, the control voltage after the mute setting is canceled is the same control voltage as the mute setting stored in the second storage means, and the variable gain is set by the control voltage. The gain in the amplification means is controlled. As a result, even when the mute setting is made, it is possible to suppress an increase in the transmission output and obtain a predetermined output in a short time.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing an embodiment of a transmission output control circuit of the present invention.

In this embodiment, as shown in FIG. 1, a frequency converter 1 which is a frequency converting means for converting an input signal into a radio frequency signal and outputting the radio signal based on an input local oscillation signal.
And a variable gain amplifier 2 which is a variable gain amplifying means for amplifying and outputting the signal output from the frequency converter 1 at the gain, the gain varying according to the input control voltage, and the variable gain amplifier 2. Detects the level of the signal output from
A level detector 3 which is a transmission output detecting means for converting the level of the detected signal into a voltage signal and outputs the voltage signal, and an A / D converter for converting the voltage signal output from the level detector 3 into a digital signal and outputting the digital signal 4, a correction voltage of the control voltage applied to the variable gain amplifier 2 and a memory 8 serving as a first storage means for storing a value for setting a local oscillation signal input to the frequency converter 1, and an input. The local oscillator signal is generated based on the control signal and is output to the frequency converter 1. The synthesizer 9 is a local oscillator signal generating means, and the output frequency and output level of the signal output from the variable gain amplifier 2 are changed. An external setting signal is input, and based on the external setting signal and the value for setting the local transmission signal stored in the memory 8, the local transmission signal generated by the synthesizer 9 is generated. The control stored in the memory 8 is generated so that the control signal for controlling the wave number is generated and output, and the output level of the signal output from the variable gain amplifier 2 becomes the output level instructed by the external setting signal. Based on the voltage correction value and the level of the signal output from the A / D converter 4, the CPU 7 that is a gain control unit that calculates and outputs the control voltage input to the variable gain amplifier 2
And a memory 6 which is a second storage means for storing the control voltage output from the CPU 7, and a D / A converter 5 which converts the control voltage output from the CPU 7 into an analog signal and outputs the analog signal. On the basis of the control signal output from the CPU 7, the synthesizer 9 generates a local oscillation signal such that the frequency of the signal output from the frequency converter 1 becomes the frequency instructed by the external setting signal. The CPU 7 can also be integrated by incorporating the function of the memory 6.

The operation of the transmission output control circuit configured as above will be described below. First, an input signal input from the outside is converted into a radio frequency signal in the frequency converter 1 and output.

Next, in the variable gain amplifier 2, the signal output from the frequency converter 1 is amplified with a predetermined gain,
It is output through the output terminal.

The signal output from the variable gain amplifier 2 is also input to the level detector 3, and the level detector 3 detects the level of the signal output from the variable gain amplifier 2 and converts it into a voltage value. Is output.

Next, in the A / D converter 4, the signal output from the level detector 3 is converted into a digital signal and output to the CPU 7.

In the CPU 7, an external setting signal of the output level and output frequency of the signal output from the variable gain amplifier 2 is input, and a value for setting the external setting signal and the local oscillation signal stored in the memory 8. Based on and
A control signal for controlling the frequency of the local oscillation signal generated by the synthesizer 9 is generated and output to the synthesizer 9, and the output level of the signal output from the variable gain amplifier 2 is changed by the external setting signal. The control voltage is calculated based on the correction value of the control voltage stored in the memory 8 and the digital signal output from the A / D converter 4 so as to reach the instructed output level.
It is output to the A converter 5. The control voltage output from the CPU 7 is always stored in the memory 6.

In the D / A converter 5, the input control voltage signal is converted into an analog signal and output to the variable gain amplifier 2.

On the other hand, in the synthesizer 9, the CPU
Based on the control signal output from the frequency converter 1, the frequency converter 1
The local oscillation signal is generated such that the frequency of the signal output from the external setting signal becomes the frequency, and is output to the frequency converter 1.

After that, in the frequency converter 1, the input signal is converted into a radio frequency signal based on the local oscillation signal output from the synthesizer 9, and the variable gain amplifier 2 outputs it from the D / A converter 5. The gain changes based on the control voltage, and the signal output from the frequency converter 1 is amplified by the gain and output via the output terminal.

Therefore, the transmission output control circuit of this embodiment includes the level detector 3, the A / D converter 4, the CPU 7, and
AG by the D / A converter 5 and the variable gain amplifier 2
A C circuit is configured.

Here, when the level of the transmission output is set to mute (output is cut off) by the external setting signal input to the CPU 7, the CPU 7 receives a control voltage that minimizes the gain of the variable gain amplifier 2. The calculated output power is controlled to the minimum value during the mute state. At this time, the control voltage when the mute is set is stored in the memory 6.

After that, when the mute setting is released by the external setting signal, the CPU 7 reads the control voltage for the mute setting stored in the memory 6, and the read voltage is read by the D / A converter 5. It is converted into an analog signal and output to the variable gain amplifier 2, and thereafter, normal AGC control is performed.

As described above, the control voltage output from the CPU 7 is stored in the memory 6, and the control voltage after the mute setting is released becomes the same control voltage as that stored in the memory 6 when the mute is set, and is changed by the control voltage. The gain in the gain amplifier 2 is controlled. This makes it possible to prevent the transmission output from increasing and to obtain a predetermined output in a short time.

FIG. 2 is a diagram showing a radio device of a hot standby system, which uses two transmitters using the transmission output control circuit shown in FIG.

In the present embodiment, as shown in FIG. 2, a transmitter 21 that outputs an output signal having an amplitude level designated by an external setting signal a and an output signal having an amplitude level designated by an external setting signal b. Transmitting device 22 for outputting
And the output signal output from the transmitter 21 and the transmitter 2
2 and the combiner 23 that combines and outputs the output signals output from the transmitters 21 and 22. The transmitters 21 and 22 are respectively provided with the transmission output control circuits shown in FIG.

In the wireless device configured as described above, one of the output signal of the transmission device 21 and the output signal of the transmission device 22 outputs a predetermined output signal, and the other output signal is muted. It is in a state. For example, the transmitter 2
When 1 fails, the transmitter 21 is set to the mute state by the external setting signal a, and the transmitter 22 is set to the state of outputting a predetermined output signal by the external setting signal b.

In order to shorten the switching time of the mute setting, the transmitter used in the hot standby type wireless device has a function of making the level of the output signal reach a predetermined value earlier, and a transmitter circuit and an adjacent circuit of each other. In order to prevent the above interference, the function that does not increase the predetermined value of the transmission output is required.

In the transmission output control circuit shown in FIG. 1, the control voltage at the time of mute setting is stored, the control voltage after the mute setting is released becomes the same control voltage as at the mute setting, and the control voltage is used in the variable gain amplifier. Since the configuration is such that the gain is controlled, it is possible to configure a transmitting device that satisfies the above-described requirements and realize a hot standby wireless device.

[0042]

As described above, according to the present invention, the gain changes according to the control voltage, the variable gain amplifying means for amplifying and outputting the transmission signal by the gain, and the variable gain amplifying means. Transmission output detection means for detecting the level of the output transmission output, first storage means for storing a correction value for changing the gain in the variable gain amplification means, and transmission detected by the transmission output detection means A control voltage for changing the gain in the variable gain amplifying means is generated based on the output level and the correction value stored in the first storage means,
In the transmission output control circuit including the gain control means for outputting the control voltage to the variable gain amplifying means, the second storage means for storing the control voltage output from the gain control means is provided. Even when the mute setting is made, the control voltage after the mute setting is released becomes the same control voltage as when the mute setting is made, and the control voltage can control the variable gain amplifying means. As a result, it is possible to suppress an increase in transmission output and obtain a predetermined output in a short time.

[Brief description of drawings]

FIG. 1 is a diagram showing one form of a transmission output control circuit of the present invention.

FIG. 2 is a diagram showing a hot standby type wireless device using the transmission output control circuit shown in FIG.

FIG. 3 is a diagram showing a conventional transmission output control circuit.

FIG. 4 is a diagram showing operating characteristics of a control voltage and an amplitude level of the VGA (variable gain amplifier) shown in FIG.

[Explanation of symbols]

1 frequency converter 2 Variable gain amplifier 3 level detector 4 A / D converter 5 D / A converter 6,8 memory 7 CPU 9 Synthesizer 21,22 transmitter 23 Synthesizer

Continuation of the front page (56) Reference JP-A-9-199960 (JP, A) JP-A-5-3440 (JP, A) JP-A-51-15314 (JP, A) JP-A-51-23013 (JP , A) JP-A-7-235848 (JP, A) JP-A-3-101525 (JP, A) JP-A-1-303908 (JP, A) JP-A-10-51250 (JP, A) 59-69524 (JP, U) Actually opened Sho-68-68712 (JP, U) Actually opened 64-16727 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H03G 3/20 H04B 1/04

Claims (3)

(57) [Claims] 1. A variable gain amplifying means for changing a gain according to a control voltage, amplifying and outputting a transmission signal by the gain,
A transmission output detection means for detecting the level of the transmission output output from the variable gain amplification means, a first storage means in which a correction value of the control voltage applied to the variable gain amplification means is stored, and an external setting signal. Is input and the external setting signal
If it is set to the mute state, the transmission output level
Generate a control voltage so that the bell is muted,
When the operating state is set by the external setting signal , based on the level of the transmission output detected by the transmission output detection means and the correction value of the control voltage stored in the first storage means, Gain control means for generating a control voltage for changing the gain in the variable gain amplification means and outputting the control voltage to the variable gain amplification means ;
And a second storage means for storing the control voltage output from the gain control means when the transmission output control is performed.
Radio device having two transmitters provided with a circuit in parallel
The gain control means stores the control voltage when the mute state is released after the mute state is set , in the mute setting control stored in the second storage means. with the voltage, set to one transmission apparatus operating state of the two transmission devices
When set, the other transmitter will be muted
Wireless apparatus characterized by being. 2. The wireless device according to claim 1 , wherein when the operation of the transmitting device in the operating state is stopped, the transmitting device in the mute state is in the operating state. 3. The wireless device of claim 1 or claim 2, the wireless apparatus characterized by having a synthesizer for outputting a signal output from the two transmission devices synthesized and.