JPH04320104A - Apc equipment for transmitter - Google Patents

Abstract

PURPOSE:To realize the inexpensive APC equipment operated stably for broad range transmission frequencies. CONSTITUTION:A transmission signal modulated in response to a modulation signal is outputted from a VCO circuit 1, amplified by an amplifier circuit 2 and sent from an antenna 14 via a filter 4. A storage circuit 15 stores data relating to a reference transmission output corresponding to the transmission frequency and a control section 8 reads the data and gives it to a reference level generating circuit 11. The reference level generating circuit 11 sends the reference level in response to the data to a level comparator circuit 5, which compares the reference level with a transmission output level from a transmission output detection circuit 6. An amplification factor control circuit 3 controls the amplification factor of the amplifier circuit 2 in response to the result of comparison to make the transmission output level constant.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is a transmitter APC device (auto power
control device).

0002

2. Description of the Related Art FIG. 6 shows a conventional APC device for a transmitter in a car telephone or the like. In the figure, 1 is a voltage controlled oscillator (VCO) circuit, 2 is an amplifier circuit, 4 is a filter, and 5 is a voltage controlled oscillator (VCO) circuit.
is a level comparison circuit, 6 is a transmission output detection circuit, 7 is a reference level generation circuit, 8 is a control unit (CPU), 9 is an input device,
10 is a reference oscillator, 11 is a phase comparator, 12 is a frequency dividing circuit, 13 is a low pass filter (LPF), and 14 is a transmitting antenna.

[0003] In the above APC device, when a transmission frequency is specified from the input device 9, the control section 8 controls the frequency dividing circuit 12.
Specify the division value. The frequency dividing circuit 12 divides the frequency of the transmission frequency signal inputted by the signal from the VCO circuit 1 based on the above-mentioned value, and applies the frequency to the phase comparator 11.

The phase comparator 11 compares the phases of the transmission frequency signal from the frequency dividing circuit 12 and the reference frequency signal from the reference oscillator 10, and outputs a pulse signal to the LPF 13 so that the phases of both signals are the same. , the LPF 13 integrates this pulse signal and applies the signal at the output voltage level to the VCO circuit 1, causing the VCO circuit 1 to oscillate at a desired frequency, the modulated high frequency signal is amplified by the amplifier circuit 2, and the filter 4 The signal is transmitted from the antenna 14 via the antenna 14. An AM or FM modulation signal is input to the VCO circuit 1, and the high frequency signal generated by the VCO circuit 1 is modulated by the modulation signal and applied to the amplifier circuit 2.

The transmission output detection circuit 6 detects and integrates the amplified transmission signal amplified by the amplifier circuit 2 to obtain a detected DC voltage level signal, and applies this signal to one input of the level comparison circuit 5.

The control unit 8 instructs the level comparison circuit 5 to apply a reference DC voltage level signal corresponding to the required transmission output level from the reference level generation circuit 7, and thereby causes the reference level generation circuit 7 to output the reference DC voltage level signal corresponding to the required transmission output level. A level signal is applied to the other input of level comparison circuit 5.

The level comparison circuit 5 compares the reference level and the actual transmission signal level based on the above two signals, and depending on the comparison result, the amplifier circuit 2 is configured to reduce the actual transmission signal level when it is too high. If it is too small,
Give an amplification factor control signal to increase the
The amplification factor of the amplifier circuit 2 is controlled according to the control signal to keep the transmission signal level constant.

[0008]

[Problem to be solved by the invention] The above-mentioned conventional APC
Although transmit filter 4 is used in the device,
In the case of a transmitter having a wide operating frequency range, since the frequency characteristics of the transmission filter 4 are as shown in FIG. 7, there is a drawback that the transmission output level is extremely reduced at the end of the transmission frequency.

[0009] In order to avoid such a phenomenon, it is necessary to use a transmission filter made of expensive parts and having flat frequency characteristics over a wide band. Further, although such measures are effective for stabilizing the transmission output level with respect to the transmission frequency, it is necessary to take other measures separately for stabilizing the conditions of temperature fluctuation and voltage fluctuation.

SUMMARY OF THE INVENTION An object of the present invention is to provide an APC device that maintains a constant transmission output level and modulation level even with wide range of transmission frequency fluctuations, temperature and voltage fluctuations, operates stably, and is inexpensive. It is in.

[0011]

[Means for Solving the Problem] In order to achieve the above object, an APC device for a transmitter according to the first invention of the present application includes a modulating means for modulating a transmission signal with a predetermined modulation signal and outputting a modulated transmission signal. , signal amplification means for amplifying the modulated transmission signal by a predetermined amplification factor and outputting the obtained transmission amplification signal from the antenna, so that the level of the transmission amplification signal output from the signal amplification means is stabilized. In the APC device of the transmitter to be controlled, a frequency setting means for specifying the frequency of the modulated transmission signal and outputting a frequency setting signal, and a data storage means for storing predetermined reference data corresponding to the frequency setting signal; Reading reference data corresponding to the set frequency from the data storage means, outputting a predetermined reference control signal corresponding to the reference data to the signal amplification means, and adjusting the amplification factor of the signal amplification means according to the transmission frequency. and a control means that controls the level of the amplified transmission signal to be constant, and adjusts the level of the amplified transmission signal according to fluctuations in the transmission frequency so that the transmission output is constant. shall be.

[0012] Further, an APC device according to a second invention of the present application is the device of the first invention, and further includes level detection means for detecting the level of the transmission amplified signal and outputting a level detection signal, and a level detection means for detecting the level of the transmission amplified signal and outputting a level detection signal, and a comparison means for comparing the level with a reference signal of the signal and controlling the amplification factor of the signal amplification means based on the comparison result, the control means comprising:
It is characterized in that reference data corresponding to the frequency setting signal is read from the data storage means, and a predetermined reference control signal corresponding to the reference data is output to the comparison means.

Furthermore, the APC device according to the third invention of the present application includes a modulation means for modulating a transmission signal with a predetermined modulation signal and outputting a modulated transmission signal, and a modulation means for amplifying the modulation transmission signal by a predetermined amplification factor. A signal amplification means for outputting a transmission amplification signal from an antenna, and an APC device for a transmitter that controls so that the level of the transmission amplification signal outputted from the signal amplification means is stabilized. power supply voltage detection means for detecting fluctuations in the power supply voltage and outputting a voltage detection signal; level setting means for specifying the amplification level of the transmission signal and outputting a level setting signal; data storage means for storing predetermined reference data; reference data corresponding to the set level setting signal is read from the data storage means; and a predetermined reference control signal corresponding to the reference data is output to the signal amplification means. and based on the voltage detection signal,
control means for controlling the amplification factor of the signal amplification means to keep the level of the amplified transmission signal constant, and adjusting the level of the amplified transmission signal according to fluctuations in the power supply voltage so that the transmission output is constant. It is characterized by making it so that

[0014]

[Operation] In the APC device of the first invention, the modulating means modulates the transmission signal with a predetermined modulation signal, and sends the modulated transmission signal to the antenna via the amplification means. The data storage means stores reference data corresponding to a frequency setting signal specifying the frequency of the modulated transmission signal. Reference data corresponding to the set frequency is read from the data storage means, and the amplification factor of the amplification means is controlled according to the transmission frequency using a reference control signal corresponding thereto, so that the transmission output becomes constant.

[0015] Furthermore, in the APC device of the second invention, the level of the transmission amplified signal output from the amplification means is detected;
The level detection signal is compared with the level of a predetermined reference signal. Based on the comparison result, the amplification factor is controlled. The reference signal is controlled by a predetermined reference control signal corresponding to the reference data.

Furthermore, in the apparatus of the third aspect of the invention, the data storage means stores reference data corresponding to a level setting signal specifying the amplification level of the transmission signal. Reference data corresponding to the set level is read from this data storage means, and a reference control signal corresponding to this is used to control the amplification factor of the amplification means in accordance with the voltage detection signal so that the transmission output is constant. .

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments shown in the drawings. FIG. 1 shows an embodiment of the APC device of a transmitter according to the present invention, in which the same reference numerals as in FIG. 6 indicate the same or similar circuits,
Furthermore, a memory circuit 15 is provided. A method for storing reference data corresponding to a frequency setting signal specifying the frequency of a transmission signal in the storage circuit 15 is performed, for example, as shown in FIG. 2.

In FIG. 2, 20 is A of the configuration shown in FIG.
A transmitter having a PC device, 21 a power meter, and 22 a control device such as a computer. First, the control device 22
specifies a transmission frequency for the transmitter 20 and causes it to transmit. The power meter 21 measures the transmission output transmitted from the transmitter 20.
Measured by The control device 22 reads the measured value of the transmission output, and sends digital data to the transmitter 20 to increase the measured value if it is lower than the required transmission level, or to lower it if it is higher. .

When the transmitter 20 receives the digital data, it changes the transmission output level by applying it to the reference level generating circuit 11. By changing the transmission output level of the transmitter 20 as described above, the control device 22 changes the transmission output level of the transmitter 20 when the necessary transmission output level is obtained.
Sends a memory command to 0. In response to the storage command, the transmitter 20 stores the digital data (reference data) that was being added to the reference level generation circuit 11 at that time in the storage circuit 15 in correspondence with the transmission frequency.

The control device 22 changes the transmission frequency and performs the same operation as described above, measures all the necessary transmission frequencies, and determines the standards to be applied to each transmission frequency and the corresponding reference level generation circuit 11. The data is stored in the storage circuit 15 in association with each transmission frequency.

After the reference data is stored as described above, the APC device of FIG. 1 operates as follows. FIG. 3 is a flowchart for explaining the above operation, and step ST1 stores the reference data mentioned above in the storage circuit 15.
The following shows the memorization operation.

The control unit 8 receives frequency designation information from the input device 9 (step ST2), and in order to obtain the output level of the transmission signal corresponding to the frequency, the control unit 8 operates the reference level generation circuit 11.
Control is performed so that the value to be given to is selected from data stored in advance in the storage circuit 15 using the method of step ST1.

It is checked whether there is a request to change the transmission frequency from the input device 9 (step ST3), and if there is no request for change (
If NO), the process returns to step ST2. If there is a request for change (YES), the control unit 8 reads out reference data for generating a reference voltage level corresponding to the transmission frequency from the storage circuit 15 (step ST4), and stores the read data in the reference level generation circuit. 11 (step ST5).

[0024] Through the above-described operation, transmission can be sent more stably against changes in transmission frequency than in the conventional system. Note that the reference level generation circuit 11 uses (a) a method in which a digital signal (reference data) from the control section 8 is converted into an analog signal level by a D/A converter, and (b) a variable width pulse signal from the control section 8. (c) A method in which a clock signal from the control unit 8 is converted into an analog signal label by an F/V converter, and the like can be used.

Further, when setting a plurality of transmission output levels is required, the value of the reference voltage level is determined by storing level data (reference data) corresponding to each output level in advance in the storage circuit 15 at the time of the above-mentioned adjustment. By storing only level data corresponding to one output level in the storage circuit 15 at the time of adjustment and adding a certain offset value to this, It is possible to use a method of obtaining the remaining level data, or a method using a predetermined calculation formula.

In addition, the APC device of the present invention can be used even when setting a plurality of transmission output levels is not necessary, and the storage circuit stores correction data corresponding to temperature fluctuations, power supply voltage fluctuations, etc. in addition to frequency. 15, and by adding these correction data to the level data and giving it to the reference level generation circuit 11, it becomes possible to maintain a stable transmission level without providing a special circuit. .

FIG. 4 shows another embodiment of the APC device according to the present invention for compensating for power supply voltage fluctuations, in which the same reference numerals as in FIG. 1 indicate the same or similar circuits, 16 is a power supply voltage detection circuit, and 17 is a power supply voltage detection circuit. The modulation circuit 18 is an oscillator. When the power supply voltage applied to the transmission output detection circuit 6 fluctuates, the output DC voltage of the transmission output detection circuit 6 changes in conjunction with the fluctuation of the power supply voltage. In order to compensate for this, the APC shown in FIG.
A device is used.

As is clear from the above description, the APC device shown in FIG. 4 only needs to add the power supply voltage detection circuit 16 to the configuration shown in FIG. Alternatively, by adopting the configuration shown in FIG. 1, it is possible to compensate for power supply voltage fluctuations and/or frequency characteristics.

Next, referring to the flow chart of FIG.
The operation of the embodiment will be explained. The control unit 8 receives voltage data from the power supply voltage detection circuit 16 under certain power supply voltage conditions,
A value (reference data) to be given to the reference level generation circuit 11 in order to obtain the output level of the transmission signal required at that time is stored in advance in the storage circuit 15 (step ST1).

The high frequency signal oscillated by the oscillator 18 is applied to the modulation circuit 17, and this high frequency signal is modulated by the modulation signal and applied to the amplifier circuit 2. Transmission output circuit 6
detects the output signal of the amplifier circuit 2, integrates it to obtain a DC voltage level signal, and applies it to the level comparison circuit 5.

The control section 8 determines whether or not there is a change in the signal output level from the input device 9 (step ST2), and selects YES.
If so, the process proceeds to step ST5, which will be described later. If NO, the detected voltage information is obtained from the power supply voltage detection circuit 16 (step ST3), and it is determined whether or not the power supply voltage has changed; if NO, the process proceeds to step ST5. Return to step ST2, but YES
If so, the process advances to step ST5. In step ST5, the control section 8 reads data for generating a reference voltage level corresponding to the power supply voltage from the storage circuit 15 and supplies it to the reference level generation circuit 11 (step ST6
).

The reference level generation circuit 11 applies a DC voltage level signal corresponding to the transmission output level to the level comparison circuit 5. The level comparison circuit 5 compares the reference level and the actual transmission level, and tells the amplifier circuit 2 to decrease the actual transmission level when it is too high, and to increase it when the actual transmission level is too low. A transmission signal whose transmission output level has been amplified to a constant level by applying a reference control signal is output from the amplifier circuit 2, and transmitted from the antenna 14 via the filter 4.

FIG. 8 shows the power supply voltage of 13.7V in the present invention.
9 is a graph showing the relationship between the power supply voltage and the transmission output when the transmission frequency is 836.52 MHz in the present invention, and FIG. 10 is the power supply voltage in the conventional circuit. A graph showing the relationship between the transmission frequency and the transmission output when the voltage is 13.7V. FIG. 11 is a graph showing the relationship between the power supply voltage and the transmission output when the transmission frequency is 836.52MHz in a conventional circuit. As is clear from the above figures, it can be seen that according to the present invention, the stability of the transmission output is improved compared to the conventional method.

[0034]

As explained above, according to the APC device of the present invention, the reference level corresponding to the transmission frequency is stored for each device, and this is read out at the time of transmission to control the transmission level. It is possible to achieve stable operation regardless of frequency characteristics such as, etc., and moreover, it is possible to use inexpensive components, and it is not dependent on variations in the components. In addition, even when the power supply voltage fluctuates, the transmitting output level can be kept stable simply by providing a power supply voltage detection circuit without using an expensive stabilizing power supply circuit, which has a great practical effect. be.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of an APC device according to the present invention.

FIG. 2 is a block diagram for explaining an adjustment method for setting the transmission frequency of the device in FIG. 1;

FIG. 3 is a flowchart of control operations according to the embodiment of FIG. 1;

FIG. 4 is a block diagram showing another embodiment of the APC device according to the present invention.

FIG. 5 is a flowchart of control operations according to the embodiment of FIG. 4;

FIG. 6 is a block diagram showing a conventional APC device.

FIG. 7 is a frequency characteristic diagram of a filter in the device of FIG. 6;

FIG. 8 is a graph showing the relationship between transmission frequency and transmission output when the power supply voltage is 13.7V in the present invention.

[Figure 9] Transmission frequency 836.52MHz in the present invention
3 is a graph showing the relationship between power supply voltage and transmission output when .

FIG. 10 is a graph showing the relationship between transmission frequency and transmission output when the power supply voltage is 13.7V in a conventional circuit.

[Figure 11] Transmission frequency 836.52 in conventional circuit
It is a graph showing the relationship between power supply voltage and transmission output at MHz.

[Explanation of symbols]

1 VCO circuit 2 Amplifier circuit 5 Level comparison circuit 6 Transmission output detection circuit 7 Reference level generation circuit 8 Control section 9 Input device 15 Memory circuit 16 Power supply voltage detection circuit

Claims (3)

[Claims] 1. Modulating means for modulating a transmission signal with a predetermined modulation signal and outputting a modulated transmission signal, and a signal amplification device for amplifying the modulated transmission signal by a predetermined amplification factor and outputting the obtained transmission amplification signal from an antenna. In an APC device for a transmitter that controls the level of the amplified transmission signal outputted from the signal amplification means to be stable, the APC device comprises: a frequency for specifying a frequency of the modulated transmission signal and outputting a frequency setting signal; a setting means, a data storage means for storing predetermined reference data corresponding to the frequency setting signal, and a data storage means for reading out the reference data corresponding to the set frequency from the data storage means and predetermined data according to the reference data. control means for outputting a reference control signal to the signal amplification means and controlling the amplification factor of the signal amplification means according to the transmission frequency to keep the level of the transmission amplification signal constant; An APC device for a transmitter, characterized in that the transmitting amplification signal level is adjusted according to fluctuations so that the transmitting output becomes constant. 2. Level detecting means for detecting the level of the transmitted amplified signal and outputting a level detection signal, and comparing the level of the level detection signal and a predetermined reference signal, comparison means for controlling the amplification factor of the amplification means, the control means reading reference data corresponding to the frequency setting signal from the data storage means, and generating a predetermined reference control signal according to the reference data. The APC device for a transmitter according to claim 1, wherein the APC device outputs the signal to the comparison means. 3. Modulation means for modulating a transmission signal with a predetermined modulation signal and outputting a modulated transmission signal, and a signal amplification device for amplifying the modulated transmission signal by a predetermined amplification factor and outputting the obtained transmission amplification signal from an antenna. In an APC device for a transmitter, which controls the level of the transmission amplification signal outputted from the signal amplification means to be stable, the APC device includes: power supply voltage detection means for outputting a detection signal; level setting means for specifying the amplification level of the transmission signal and outputting a level setting signal; and data storage for storing predetermined reference data corresponding to the level setting signal. reading out reference data corresponding to the set level setting signal from the data storage means, outputting a predetermined reference control signal corresponding to the reference data to the signal amplification means, and based on the voltage detection signal, control means for controlling the amplification factor of the signal amplification means to keep the level of the amplified transmission signal constant, and adjusting the level of the amplified transmission signal according to fluctuations in the power supply voltage so that the transmission output is constant. An APC device for a transmitter, characterized in that: