JP2001168746A - Receiver and transmitter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a receiver capable of reducing power consumption in reception. SOLUTION: In this receiver, a high frequency amplifier 2 or the like is operated only for the time required for demodulating information included in received amplitude modulated waves. To this end, a pulse generation circuit 111 generates pulses composed of a frequency for satisfying the above condition and power from a power source 12 passes through an AND gate 112 when the pulse of the pulse generation circuit 111 is at an H level. The passing power is supplied to the high frequency amplifier 2, a local oscillator 3, a frequency converter 4, an intermediate frequency amplifier 6 and a sample-and-hold circuit 8 respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a receiver capable of reducing power consumption of a high-frequency amplifier and the like during reception, and to a transmitter capable of reducing power consumption of a power amplifier during transmission. .

[0002]

2. Description of the Related Art Conventionally, as an example of a circuit configuration of a receiver for receiving sound, a high-frequency amplifier, a local oscillator, a frequency converter, a band-pass filter, an intermediate frequency amplifier, a demodulator, A device including a low-frequency amplifier is known.

In a conventional receiver having such a configuration, a high-frequency signal corresponding to a radio wave received by an antenna is amplified by a high-frequency amplifier, and the amplified high-frequency signal is input to a frequency converter. The frequency converter outputs a converted signal having a frequency Fo = (Fi-Fl), where Fi is the frequency of the input high-frequency signal and Fl is the oscillation frequency of the local oscillator.

[0004] Since the frequency of the local oscillator is variable, the frequency of the converted signal of the frequency converter is always constant even if the frequency of the high-frequency signal varies according to the received radio wave. After the output signal of the frequency conversion unit is band-limited by the band-pass filter, the signal is amplified by the intermediate frequency amplification unit, and the audio signal included in the output signal of the intermediate frequency amplification unit is demodulated by the demodulation unit. The audio signal is amplified by the low frequency amplifier.

[0005]

By the way, in the conventional receiver, the power is always applied from the power supply to the high frequency amplifying unit and the like at the time of reception, so that the receiver is operated. In general, a high-frequency amplifier requires a large current, for example, about 5 mA, in an amplification element in order to secure a sufficient S / N ratio of a receiving system.
Requires large power. Therefore, the conventional receiver has a disadvantage that power consumption at the time of reception is large, and it has been desired to solve this disadvantage.

On the other hand, a conventional analog modulation type transmitter or the like includes a power amplifying unit for amplifying a modulated wave obtained by changing a parameter of a carrier according to information. However, in the conventional transmitter, the power is always applied from the power supply to the power amplifying unit at the time of transmission so that the power amplifying unit is activated. In general, the power amplifying unit of the transmitter requires a large amount of power, so that the conventional transmitter consumes wasteful power, and this solution has been desired.

Accordingly, a first object of the present invention is to provide a receiver capable of reducing power consumption during reception in view of the above points.

[0008] A second object of the present invention is to solve the above problems,
An object of the present invention is to provide a transmitter capable of reducing power consumption during transmission.

[0009]

In order to solve the above problems and to achieve the first object of the present invention, claims 1 to 3 are provided.
The invention described in (1) is configured as follows.

That is, the invention according to claim 1 includes a high-frequency amplifier for amplifying a received high-frequency signal and demodulating information contained in the amplified high-frequency signal. The high-frequency amplifier is operated for a time necessary for demodulating information from the high-frequency signal.

According to a second aspect of the present invention, in the receiver according to the first aspect, a pulse generator for generating a pulse of a predetermined frequency, and the high-frequency amplifier is controlled by the pulse generated by the pulse generator. And a control unit for controlling on / off of the supplied power.

According to a third aspect of the present invention, in the receiver according to the first or second aspect, the information is an audio signal.

As described above, according to the receiver of the present invention, at the time of reception, the high-frequency amplifier particularly consuming a large amount of power is operated only for the time necessary for demodulating information from the high-frequency signal. Thus, power consumption during reception can be significantly reduced.

Next, in order to achieve the second object of the present invention, the inventions according to claims 4 to 6 are configured as follows.

That is, according to a fourth aspect of the present invention, there is provided a transmitter including a power amplifying unit for amplifying a modulated wave in which a parameter of a carrier wave is changed according to information. The power amplifier is operated intermittently within a range not to be lost.

Here, the transmitter of the present invention can be applied to both an analog system and a digital system. The above-mentioned parameter of the carrier is the amplitude, frequency or phase of the carrier.

According to a fifth aspect of the present invention, in the transmitter according to the fourth aspect, a pulse generating section for generating a pulse of a predetermined frequency, and the power amplifying section is controlled by the pulse generated by the pulse generating section. And a control unit for controlling on / off of the supplied power.

According to a sixth aspect of the present invention, in the transmitter according to the fourth or fifth aspect, the information is an audio signal.

As described above, according to the transmitter of the present invention, at the time of transmission, the power amplifying unit particularly consuming a large amount of power is operated intermittently within a range where the modulated wave does not lose information. Can significantly reduce power consumption.

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

The configuration of an embodiment of the receiver according to the present invention will be described with reference to the block diagram of FIG.

The receiver according to this embodiment is an analog receiver that receives an amplitude-modulated wave obtained by amplitude-modulating a carrier wave with an audio signal (AM modulation). As shown in FIG. 2, a local oscillator 3, a frequency conversion unit 4, a band-pass filter (BPF) 5, an intermediate frequency amplification unit 6, a demodulation unit 7, a sample hold unit 8,
A low-frequency amplifier 9 and a speaker 10 are provided.

In the receiver according to this embodiment,
As shown in FIG. 1, a power control unit 11 is provided in order to reduce power consumption at the time of reception, and a high-frequency amplifier 2, a local oscillator 3, a frequency converter 4, a band-pass The power supply 12 is connected to the filter 5, the intermediate frequency amplifying unit 6, and the sample hold unit 8 via the power control unit 11.
Is intermittently supplied, and the other components are always supplied with power from the power supply 12. The power supply 12 is a DC power supply including, for example, a battery.

More specifically, a high-frequency signal corresponding to a radio wave received by the antenna 1 is amplified by the high-frequency amplifier 2 for a time necessary for demodulating information contained in the high-frequency signal, and the amplified signal is amplified. The high-frequency signal is input to the frequency converter 4. Frequency converter 4
When the frequency of the high-frequency signal input from the high-frequency amplifier 2 is Fi and the oscillation frequency of the local oscillator 3 is F1, an output signal having a frequency Fo = (Fi-Fl) is output.

The oscillation frequency of the local oscillator 3 is variable according to the frequency of the received radio wave, so that the frequency Fo of the output signal of the frequency converter 4 is always constant. The output signal of the frequency converter 4 is band-limited by the band-pass filter 5 and then amplified by the intermediate frequency amplifier 6. The signal included in the output signal of the intermediate frequency amplifier 6 is demodulated by the demodulator 7. It has become. The signal demodulated by the demodulation unit 7 is sampled and held by a sample and hold circuit 8 and then amplified by a low frequency amplification unit 9 to drive a speaker 10.

As shown in FIG. 1, the power control section 11 includes a pulse generation section 111 for generating a pulse of a predetermined frequency, and an AND section for controlling the passage of power from the power supply 12 in accordance with the output of the pulse generation section 111. This power control allows the power consumption of the high-frequency amplifier 2 and the like to be greatly reduced during reception.

Next, the operation of the receiver according to the embodiment having such a configuration will be described.

This receiver receives an amplitude-modulated wave as shown in FIG. This amplitude modulated wave is shown in FIG.
As shown in (1), the amplitude of the carrier changes with the audio signal, and the envelope coincides with the original audio signal. Reproduce (demodulate) the original audio signal from such an amplitude modulated wave
In this case, it is not necessary to continuously receive the amplitude-modulated wave as in the related art, but it is possible to receive the amplitude-modulated wave intermittently.

In the case of intermittent reception, in order to reproduce the original audio signal, sampling is performed at the maximum frequency of the envelope, that is, at a period T of a frequency 2Fm which is twice the maximum frequency Fm of the original audio signal. Is reproducible (sampling theorem). For example, if the frequency range of the audio signal is 0 to 5 KHz, Ｆ Fm = 1/10 KH
If an amplitude-modulated wave is received at a period of z = 0.1 ms, the audio signal can be reproduced up to 5 KHz.

Therefore, in the receiver of this embodiment, the amplitude-modulated wave is intermittently received so as to satisfy the above condition (see FIG. 2B) and signal processing is performed. For example, the power from the power supply 12 is intermittently supplied via the power control unit 11 (see FIG. 2).
(C)).

That is, the pulse generation circuit 111 generates a pulse having a frequency of, for example, 10 KHz. When the pulse of the pulse generation circuit 111 is at the H level, the power from the power supply 12 passes through the AND gate 112, and the passing power Is supplied to the high-frequency amplifier 2, the local oscillator 3, the frequency converter 4, the intermediate-frequency amplifier 6, and the sample-and-hold circuit 8, respectively.

As described above, in the receiver according to this embodiment, the high-frequency amplifier 2 and the like are operated only for the time necessary for demodulating the information contained in the received amplitude modulated wave. In addition, power consumption during reception can be reduced, and the power source can be downsized.

In the above embodiment, the case where the present invention is applied to an analog receiver for receiving an amplitude modulated wave has been described. However, the idea of the present invention is, in addition to an analog receiver that receives a frequency modulation wave other than an amplitude modulation wave, a phase modulation wave, a single sideband signal, and a spread spectrum signal,
Needless to say, the present invention can be applied to all systems that transmit and receive a desired signal on a high-frequency carrier, such as a digital receiver that receives various digital modulation waves such as a spread spectrum signal.

In the above embodiment, the power control unit 1
1 is a high-frequency amplifier 2, a local oscillator 3, a frequency converter 4,
Although the power supplied to all of the band-pass filter 5, the intermediate frequency amplifier 6, and the sample-and-hold unit 8 is controlled, the present invention is not limited to this, and the power supplied to at least one of these circuits is controlled. However, a predetermined effect can be obtained.

Next, an embodiment of the transmitter of the present invention will be described.

The transmitter according to this embodiment includes a power amplifier for power-amplifying an amplitude-modulated wave in which the amplitude, which is one of the parameters of the carrier, is changed in accordance with the audio signal. The power amplifier is operated intermittently within a range in which the amplitude modulated wave does not lose a voice signal (information). Then, in order to realize the intermittent operation of the power amplifying section, the circuit corresponding to the power control section 11 shown in FIG. 1 intermittently supplies power to the power amplifying section.

As described above, in the transmitter according to this embodiment, the power amplifying unit, which consumes particularly large power, is operated intermittently during transmission within a range where the amplitude modulated wave does not lose information. Thus, power consumption during transmission can be significantly reduced, and the power source can be downsized.

In the above-described embodiment, the case where the present invention is applied to an analog transmitter for amplifying power of an amplitude-modulated wave has been described. However, the concept of the present invention is, of course, applicable to digital transmitters for power-amplifying various digitally modulated waves in addition to analog transmitters for power-amplifying frequency-modulated waves and phase-modulated waves other than amplitude-modulated waves. It is.

[0039]

As described above, in the receiver according to the present invention, the high-frequency amplifying unit, which consumes a large amount of power, is used during reception.
Since the operation is performed only for a time necessary for demodulating information from the high-frequency signal, power consumption during reception can be significantly reduced.

Further, in the transmitter of the present invention, the power amplifying section, which consumes particularly large power, is operated intermittently during transmission so that the modulated wave does not lose information. It can be greatly reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an embodiment of a receiver according to the present invention.

FIG. 2 is a waveform diagram illustrating the operation of the receiver in FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 antenna 2 high-frequency amplifier 3 local oscillator 4 frequency converter 5 band-pass filter 6 intermediate-frequency amplifier 7 demodulator 8 sample-hold circuit 9 low-frequency amplifier 10 speaker 11 power controller 12 power supply 111 pulse generator 112 and gate

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 5K067 AA43 KK00 KK05

Claims (6)

[Claims] 1. A receiver comprising a high-frequency amplifier for amplifying a received high-frequency signal and demodulating information contained in the amplified high-frequency signal. A receiver characterized in that the high-frequency amplifier is operated only for a time necessary for demodulation. 2. A pulse generator for generating a pulse having a predetermined frequency, and a controller for controlling on / off of electric power supplied to the high-frequency amplifier by a pulse generated by the pulse generator. The receiver according to claim 1, wherein: 3. The receiver according to claim 1, wherein the information is an audio signal. 4. A transmitter including a power amplifying unit for amplifying a modulated wave in which a parameter of a carrier is changed according to information, wherein the power amplifying unit does not lose the information during transmission when transmitting. A receiver characterized by being operated intermittently. 5. A pulse generator for generating a pulse of a predetermined frequency, and a controller for controlling on / off of power supplied to the power amplifier by a pulse generated by the pulse generator. The transmitter according to claim 4, wherein: 6. The transmitter according to claim 4, wherein the information is an audio signal.