JP2000022560A - Apc circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To omit a detector circuit and accordingly to omit a feedback loop in order to obtain a small and lightweight APC circuit by applying the corresponding gain control voltage decided from the detected signal of a temperature sensor based on the memory contents of a storage part to an automatic gain control amplifier. SOLUTION: An RF signal is inputted to an automatic gain control amplifier 1, and an output signal is inputted to a shared device 3 via a power amplifier 2. In a series of this flow, the output levels of the amplifiers 1 and 2 vary in response to the change of temperature and frequency since both amplifiers 1 and 2 have the temperature and frequency characteristics. In this respect, the ambient temperature is detected by a temperature sensor 7 and inputted to a control part 9 as a digital signal. The part 9 outputs an appropriate gain control voltage signal based on the received digital signal and the data stored in a 1st storage part 8. The digital output signal received from the part 9 is converted into an analog signal by a D/A converter 5 and inputted to the amplifier 1. Thus, the varying output level depending on the change of the ambient temperature can be always kept constant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an APC (Auto
More particularly, the present invention relates to a method for maintaining a constant output level of an RF signal without using a feedback loop.

[0002]

2. Description of the Related Art FIG. 4 is a block diagram of a conventional APC circuit. The conventional APC circuit of FIG. 4 has the following configuration.

[0003] 1 is an automatic gain control type amplifier (AGCAMP) for automatically adjusting the gain, 2 is a power amplifier, 3 is 1
A duplexer for simultaneously using radio transmission and reception for one antenna without interaction, 4 is a detection circuit for detecting the output signal level from the power amplifier 2, 5 is a control voltage which is a digital signal and an analog signal. D /
The A converter 6 has a detection voltage and a D value detected by the detection circuit 4.
5 shows an operational amplifier that compares a control voltage converted into an analog signal by the / A converter 5.

Next, the operation of FIG. 4 will be described. The RF signal passing through the power amplifier 2 via the automatic gain control type amplifier 1 is input to the duplexer 3. At this time, a part of the RF signal passing through the power amplifier 2 is input to the detection circuit, and the detection circuit 4 detects the level of the input signal and outputs the detection voltage to the operational amplifier 6.
To enter. Further, a control voltage obtained by converting a digital signal into an analog signal by the D / A converter 5 is input to the operational amplifier 6. The operational amplifier 6 compares the input detection voltage with the control voltage and outputs a specified voltage to the automatic gain control type amplifier 1. As a result, the level of the output signal of the RF signal is maintained at the specified value by feeding back the specified voltage to the automatic gain control type amplifier 1.

[0005]

However, in a conventional circuit configuration, an analog circuit occupies an area including a detection circuit and an operational amplifier, and a mobile phone terminal or the like, which is becoming lighter and thinner, requires a larger area. In addition, there is a problem in that the current consumption is increased only by the circuit corresponding to that.

[0006]

According to an aspect of the present invention, there is provided an APC circuit, comprising: an automatic gain control type amplifier which receives an RF signal and performs gain control by a control voltage; and an automatic gain control type amplifier. A power amplifier that amplifies the output signal of the amplifier and outputs an RF signal, a temperature sensor that detects an ambient temperature and outputs a detection signal, and a storage unit that stores data corresponding to the temperature and the gain control voltage. A D / A converter for converting a digital signal into an analog signal, and a gain control voltage corresponding to the automatic gain via the D / A converter based on the detection content of the temperature sensor based on the content stored in the storage unit. And a control unit for applying the voltage to the gain control type amplifier.

Further, the APC circuit according to the second aspect of the present invention is an APC circuit,
An automatic gain control type amplifier which receives a signal and gain is controlled by a control voltage, a power amplifier which amplifies an output signal of the automatic gain control type amplifier and outputs an RF signal, a frequency code and a gain control voltage corresponded. A storage unit for storing data, and a D / D converter for converting a digital signal into an analog signal.
An A converter, and a control unit that applies a corresponding gain control voltage from a frequency code of a radio frequency to be transmitted based on the storage content of the storage unit to the automatic gain control amplifier via the D / A converter. , Is provided.

Further, the APC circuit according to the third aspect is characterized in that the APC circuit
An automatic gain control type amplifier which receives a signal and gain is controlled by a control voltage; a power amplifier which amplifies an output signal of the automatic gain control type amplifier to output an RF signal; and detects a surrounding temperature to generate a detection signal. A temperature sensor to be output, a storage unit for storing data corresponding to a temperature and frequency code and a gain control voltage, a D / A converter for converting a digital signal to an analog signal, and the temperature sensor and a radio for transmission A control unit for applying a corresponding gain control voltage from a frequency code of a frequency based on the storage content of the storage unit to the automatic gain control type amplifier via the D / A converter. I do.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The same components as those of the conventional APC circuit are denoted by the same reference numerals in the description of the embodiment of the present invention.

FIG. 1 is a block diagram showing an embodiment of an APC circuit according to the present invention. Each configuration is shown below.

1 is an automatic gain control type amplifier (AGCAMP) for automatically adjusting the gain, 2 is a power amplifier, 3 is 1
5 is a D / A converter for converting a control voltage, which is a digital signal, into an analog signal, and has the same configuration as a conventional APC circuit. Department. Reference numeral 7 denotes a temperature sensor that detects the ambient temperature and takes in the data as data.
Is a first storage unit that stores data corresponding to the detection output of the temperature sensor 7 and the gain control voltage, and 9 is a gain control voltage signal based on the detection signal of the temperature sensor 7 and the storage content of the first storage unit 8. 2 shows a control unit that controls so as to output.

Next, the operation principle of the above block diagram will be described. First, an RF signal is input to the automatic gain control amplifier 1, and an output signal is input to the duplexer 3 via the power amplifier 2. In this series of flows, since the automatic gain control type amplifier 1 and the power amplifier 2 have temperature characteristics and frequency characteristics, output levels fluctuate due to changes in temperature and frequency. Therefore, in the embodiment of FIG. 1, the ambient temperature is detected from the temperature sensor 7 and is input to the control unit 9 as a digital signal. Then, the control section 9 outputs an appropriate gain control voltage signal from the signal and the data in the first storage section 8. The digital output signal from the control unit 9 is converted into an analog signal by the D / A converter 5 and is input to the automatic gain control type amplifier 1 so that the output level that fluctuates with changes in the ambient temperature is constantly maintained. Can be constant.

FIG. 2 is provided with a second storage unit 10 for storing data corresponding to a frequency code and a gain control voltage in order to suppress the fluctuation of the output level due to the frequency fluctuation. The operation principle is as follows. First, the control unit 9 outputs a suitable gain control voltage signal based on the frequency code of the radio frequency to be transmitted and the data in the second storage unit 10.
Then, the digital output signal from the control unit 9 is converted to D /
By converting the analog signal into an analog signal by the A-converter 5 and inputting the signal to the automatic gain control type amplifier 1, the output level fluctuating with respect to the radio frequency to be transmitted can always be kept constant.
Other components are the same as those in FIG. 1 and the operation principle is also the same.

FIG. 3 shows a temperature sensor 7 for suppressing fluctuations in output level corresponding to temperature and frequency fluctuations.
A third storage section 11 stores data corresponding to the temperature and frequency code and the gain control voltage. The operating principle is that the control unit 9 outputs a suitable gain control voltage signal based on the output signal detected by the temperature sensor 7, the frequency code of the radio frequency to be transmitted, and the data in the third storage unit 11. The digital output signal from the control unit 9 is converted into an analog signal by the D / A converter 5 and is input to the automatic gain control type amplifier 1 so that the digital output signal fluctuates with changes in the ambient temperature and changes in the radio frequency to be transmitted. Output level can be kept constant at all times. Other components are the same as those in FIG. 1 and the operation principle is also the same.

Further, in the embodiment, the storage units are described separately, but may be constituted by one storage unit.

[0016]

As described above, according to the APC circuit of the present invention, there is no need for a detection circuit which is an analog circuit occupying a larger area than the conventional APC circuit, and the feedback loop is eliminated. As a result, the APC circuit does not have individually required components, which contributes to reduction in size and weight. In addition, the temperature sensor, the memory, the control unit, and the like can be commonly used, and a constant output can be obtained by controlling based on the correction data using the parameter of the RF output signal variation related to the RF output signal variation. Can be supplied. Furthermore, if it is used in a mobile phone terminal or the like that requires miniaturization and weight reduction, the proportion of the APC circuit on the substrate becomes smaller, which helps to reduce the size and weight, and reduces standby current and talk time by reducing current consumption. It becomes possible. In addition, it is possible to cope with any variation in the RF output signal by providing a sensor or the like for detecting the cause of the variation in the RF output signal and the corresponding correction data and controlling the gain by the control unit.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of a temperature sensor having a temperature sensor according to an embodiment of the present invention;
Block diagram of PC circuit

FIG. 2 shows an AP having a decoder according to an embodiment of the present invention;
Block diagram of C circuit

FIG. 3 is a block diagram of an APC circuit including a temperature sensor and a decoder according to an embodiment of the present invention.

FIG. 4 is a block diagram showing an example of a conventional APC circuit.

[Explanation of symbols]

 1: Automatic gain control type amplifier 2: Power amplifier 3: Duplexer 4: Detection circuit 5: D / A converter 6: Operational amplifier 7: Temperature sensor 8: First storage unit 9: Control unit 10: Second storage unit 11: Third storage unit

Claims (3)

[Claims] 1. An automatic gain control type amplifier which receives an RF signal and gain is controlled by a control voltage, a power amplifier which amplifies an output signal of the automatic gain control type amplifier and outputs an RF signal, A temperature sensor that detects and outputs a detection signal; a storage unit that stores data corresponding to a temperature and a gain control voltage; a D / A converter that converts a digital signal to an analog signal; A control unit for applying a corresponding gain control voltage from a detection signal based on the storage content of the storage unit to the automatic gain control type amplifier via the D / A converter;
An APC circuit comprising: 2. An automatic gain control type amplifier which receives an RF signal and gain is controlled by a control voltage, a power amplifier which amplifies an output signal of the automatic gain control type amplifier and outputs an RF signal, a frequency code and a gain. A storage unit that stores data corresponding to the control voltage; a D / A converter that converts a digital signal into an analog signal; and a corresponding unit based on the content of the storage unit based on a frequency code of a radio frequency to be transmitted. The gain control voltage is set to the D / A
A control unit for applying the automatic gain control type amplifier to the automatic gain control type amplifier via a converter. 3. An automatic gain control type amplifier which receives an RF signal and gain is controlled by a control voltage, a power amplifier which amplifies an output signal of the automatic gain control type amplifier and outputs an RF signal, A temperature sensor that detects and outputs a detection signal, a storage unit that stores data corresponding to a temperature and frequency code and a gain control voltage, a D / A converter that converts a digital signal to an analog signal, A control unit for applying a corresponding gain control voltage from the temperature sensor and the frequency code of the radio frequency to be transmitted based on the storage content of the storage unit to the automatic gain control type amplifier via the D / A converter. An APC circuit comprising: