JP2010233242A - Radio wave receiving apparatus, radio wave receiving circuit and radio wave clock - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reproduce a data signal which is not deteriorated, even when a level of a receiving signal varies by a large amount, due to noise mixture, or the like. <P>SOLUTION: In a radio wave receiving apparatus 620, an over-input control circuit 632 detects whether a signal (a) received by a receiving antenna 621 and amplified by an RF amplifying circuit 622 exceeds the dynamic range or a comparison voltage value of the radio wave receiving apparatus 620. When it exceeds, a control signal (b) for lowering (attenuating) an amplification factor of the RF amplifying circuit 622 is generated and output, according to the exceeding level of the dynamic range or the comparison voltage value of the signal (a), and also a control signal (c) for increasing the amplification factor in an enhanced circuit 626 by a part of the attenuation of the amplification factor of the RF amplifying circuit 622 by the control signal (b) is generated and is then output. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a radio wave receiver, a radio wave receiver circuit, and a radio timepiece.

  Currently, in each country (for example, Japan, Germany, United Kingdom, Switzerland, etc.), a long wave standard radio wave including time information, that is, a time code is transmitted. In Japan (Japan), 40 kHz and 60 kHz standard radio waves modulated with time codes using a long wave standard radio wave format are transmitted from two transmitting stations (Fukushima Prefecture and Saga Prefecture). This time code is transmitted in a frame of one cycle of 60 seconds every time the minute digit of the correct time is updated, that is, every minute.

  In recent years, so-called radio timepieces have been put into practical use that receive such standard radio waves with a time code and correct the current time. A radio-controlled timepiece receives a standard radio wave via a built-in antenna and corrects the current time by decoding the time code by performing amplification and detection.

  By the way, the reception signal actually received by the radio timepiece is a signal in which various signals (noise) are mixed and superimposed on the standard radio wave transmitted from the transmission station in the transmission process from the transmission station to the radio timepiece. Therefore, for example, a technique for reducing noise contained in a received signal in a signal reproduction circuit (detection circuit) that reproduces a data signal based on an intermediate frequency signal obtained by amplifying the received signal at an antenna and converting the frequency is known. (For example, refer to Patent Document 1).

JP 2004-140510 A

  By the way, the radio wave receiver has a dynamic range that is determined by the power supply voltage, etc. If the level of the received signal exceeds this dynamic range due to the increase of the mixed noise, the signal portion that exceeds the dynamic range is cut (clipped). As a result, there is a problem in that accurate data signals cannot be reproduced.

This will be specifically described.
FIG. 8A is a diagram illustrating an example of a signal waveform of a transmission signal (standard radio wave) from a transmitting station. As shown in FIG. 2A, the transmission signal is a signal with a period of 1 second having a modulation degree of 10% or 100%. However, the actual received signal in the radio wave receiver has a waveform in which the amplitude of the transmitted signal varies greatly due to noise mixing in the transmission process, as shown in FIG.

  When the signal level of the received signal exceeds the dynamic range of the radio wave receiver, the signal portion exceeding the range is cut, but the cut signal portion also includes a data component. For this reason, the data signal reproduced by the detection has a waveform in which the amplitude is partially reduced, that is, deteriorated with respect to the original data signal (time code) indicated by the dotted line in the figure, as shown in FIG. End up.

  In view of the above circumstances, an object of the present invention is to make it possible to reproduce a data signal without deteriorating it even when the level of the received signal fluctuates greatly due to noise mixing or the like.

In order to solve the above-mentioned problem, the invention described in claim 1
First amplifying means (for example, the RF amplifying circuit 622 in FIG. 2) for amplifying the received signal received by the antenna;
Filter means (for example, filter circuit 625 in FIG. 2) for extracting a signal in a predetermined frequency band from the reception signal amplified by the first amplification means;
Second amplification means (for example, IF amplification circuit 627 in FIG. 2) for further amplifying the reception signal extracted by the filter means;
Level detection means (for example, an over-input control circuit 632 in FIG. 2) for detecting whether or not the reception signal amplified by the first amplification means is within a predetermined voltage level range;
When the level detection means detects that the received signal exceeds a predetermined voltage level range, the amplification in the first amplification means is attenuated and the amplification in the second amplification means is set. Over-input control means (for example, the over-input control circuit 632 in FIG. 2) for controlling the increase;
Detection means for detecting the reception signal amplified by the second amplification means (for example, the detection circuit 629 in FIG. 2);
A radio wave receiving apparatus (for example, the radio wave receiving apparatus 620 in FIG. 2).

The invention described in claim 2 is the radio wave receiver according to claim 1,
A delay unit (for example, a delay circuit 6324 in FIG. 5) for delaying the control operation for increasing the amplification degree in the second amplifying unit;
The over-input control means attenuates the amplification degree in the first amplification means when the level detection means detects that the received signal exceeds a predetermined voltage level range, and the delay means Is controlled so as to increase after delaying the amplification degree of the second amplification means.

The invention described in claim 3 is the radio wave receiver according to claim 1,
The overinput control means continuously attenuates the amplification degree in the first amplification means when the level detection means detects that the received signal exceeds a predetermined voltage level range, The second amplifying means is controlled to increase the amplification degree continuously.

According to a fourth aspect of the present invention, in the radio wave receiver of the first aspect,
The over-input control unit attenuates the amplification degree in the first amplification unit stepwise when the level detection unit detects that the received signal exceeds a predetermined voltage level range; Control is performed such that the amplification degree of the second amplification means is increased stepwise.

The invention described in claim 5
A first amplifier circuit (for example, an RF amplifier circuit 622 in FIG. 2) that amplifies the received signal received by the antenna;
A filter circuit (for example, the filter circuit 625 in FIG. 2) that extracts a signal in a predetermined frequency band from the reception signal amplified by the first amplifier circuit;
A second amplifier circuit (for example, IF amplifier circuit 627 in FIG. 2) for further amplifying the reception signal extracted by the filter circuit;
A level detection circuit (for example, an over-input control circuit 632 in FIG. 2) for detecting whether or not the received signal amplified by the first amplifier circuit is within a predetermined voltage level range;
When the level detection circuit detects that the received signal exceeds a predetermined voltage level range, the amplification in the first amplification circuit is attenuated and the amplification in the second amplification circuit is increased. An over-input control circuit (for example, an over-input control circuit 632 in FIG. 2) that controls to increase,
A detection circuit (for example, the detection circuit 629 in FIG. 2) for detecting the reception signal amplified by the second amplification circuit;
A radio wave receiving circuit (for example, the radio wave receiving device 620 in FIG. 2).

The invention according to claim 6 is the radio wave receiving circuit according to claim 5,
A delay circuit (for example, the detection circuit 629 in FIG. 5) for delaying the control operation for increasing the amplification degree in the second amplifier circuit;
The over-input control circuit is
When the level detection circuit detects that the received signal exceeds a predetermined voltage level range, the amplification level in the first amplification circuit is attenuated, and the delay circuit causes the second amplification circuit to be attenuated. Control is performed such that the degree of amplification is increased after being delayed.

The invention according to claim 7 is the radio wave receiving circuit according to claim 5,
The over-input control circuit continuously attenuates the degree of amplification in the first amplifier circuit when the level detection circuit detects that the received signal exceeds a predetermined voltage level range, The second amplifier circuit is controlled to increase the amplification degree continuously.

The invention according to claim 8 is the radio wave receiving circuit according to claim 5,
When the level detection circuit detects that the received signal exceeds a predetermined voltage level range, the over-input control circuit attenuates the amplification degree in the first amplification circuit in stages. Control is performed so that the amplification degree of the second amplifier circuit is increased stepwise.

The invention according to claim 9 is:
First amplification means (for example, RF amplification circuit 622 in FIG. 2) for amplifying a reception signal received by a standard radio wave including time information by an antenna (for example, reception antenna 621 in FIG. 2);
Filter means (for example, filter circuit 625 in FIG. 2) for extracting a signal in a predetermined frequency band from the reception signal amplified by the first amplification means;
Second amplification means (for example, IF amplification circuit 627 in FIG. 2) for further amplifying the reception signal extracted by the filter means;
Level detection means (for example, an over-input control circuit 632 in FIG. 2) for detecting whether or not the reception signal amplified by the first amplification means is within a predetermined voltage level range;
When the level detection means detects that the received signal exceeds a predetermined voltage level range, the amplification in the first amplification means is attenuated and the amplification in the second amplification means is set. Over-input control means (for example, the over-input control circuit 632 in FIG. 2) for controlling the increase;
Detection output means (for example, the detection circuit 629 in FIG. 2) for detecting the reception signal amplified by the second amplification means and outputting it as a detection signal;
Time code generating means (for example, the time code generating unit 700 in FIG. 1) for generating time information based on the detection signal output from the detection output means;
Clocking means for clocking the current time (for example, the clock circuit unit 800 in FIG. 1);
Time correction means (for example, the CPU 100 in FIG. 1) for correcting the current time measured by the time measurement means based on the time information generated by the time code generation means;
A radio timepiece (for example, the radio timepiece 1 in FIG. 1).

  According to the first aspect of the present invention, when the received signal exceeds a certain level, after the degree of amplification in the first amplifying unit is once attenuated, the second amplifying unit responds to attenuation in the first amplifying unit, for example. Amplified by the amount. As a result, even when the level of the received signal increases due to noise or the like, the data component contained in the received signal is cut as the level of the received signal exceeds the dynamic range of the radio wave receiver as in the past. Thus, it is possible to reproduce an accurate data signal without being performed.

  According to the second aspect of the present invention, when the received signal amplified by the first amplifying unit exceeds a predetermined voltage level range, the first amplifying unit delays the attenuation of the amplification factor and The amplification degree in the second amplification means is increased. Here, a more accurate reproduction of the data signal is realized by setting the degree of amplification delay in the second amplifying means to a degree corresponding to the delay caused by the filter means.

  According to the third aspect of the present invention, when the reception signal amplified by the first amplifying means exceeds a predetermined voltage level range, the amplification degree in the first amplifying means is continuously attenuated. The amplification degree in the second amplification means is continuously increased.

  According to the fourth aspect of the present invention, when the reception signal amplified by the first amplifying means exceeds a predetermined voltage level range, the amplification degree in the first amplifying means is attenuated stepwise. The amplification degree in the second amplification means is increased stepwise.

  According to the fifth aspect of the present invention, when the received signal exceeds a certain level, after the degree of amplification in the first amplifier circuit is once attenuated, in the second amplifier circuit, for example, in the first amplifier circuit Amplified by the amount corresponding to the attenuation. As a result, even if the level of the received signal increases due to noise contamination, etc., the data component contained in the received signal is cut as the level of the received signal exceeds the dynamic range of the radio wave receiving circuit as in the past. Thus, it is possible to reproduce an accurate data signal without being performed.

  According to the sixth aspect of the present invention, when the reception signal amplified by the first amplifier circuit exceeds a predetermined voltage level range, the first amplifier circuit delays the attenuation of the amplification factor, The amplification degree in the second amplifier circuit is increased. Here, a more accurate reproduction of the data signal is realized by setting the delay of amplification in the second amplifier circuit to a level corresponding to the delay caused by the filter means.

  According to the seventh aspect of the present invention, when the reception signal amplified by the first amplifier circuit exceeds a predetermined voltage level range, the amplification degree in the first amplifier circuit is continuously attenuated. At the same time, the amplification degree in the second amplifier circuit is continuously increased.

  According to the eighth aspect of the present invention, when the reception signal amplified by the first amplifier circuit exceeds a predetermined voltage level range, the amplification degree in the first amplifier circuit is attenuated stepwise. At the same time, the degree of amplification in the second amplifier circuit is increased stepwise.

  According to the ninth aspect of the present invention, in the radio timepiece, when the received signal exceeds a certain level, after the degree of amplification in the first amplifying means is once attenuated, in the second amplifying means, for example, the first amplifying means. Is increased by an amount corresponding to the attenuation at. As a result, even when the level of the received signal is increased due to noise or the like, the data component included in the received signal is cut when the level of the received signal exceeds the dynamic range, as in the past. Reproducible accurate data signal reproduction is realized.

The block diagram of the radio timepiece in an embodiment. 1 is a configuration diagram of a superheterodyne radio wave receiver in an embodiment. FIG. The block diagram of the overinput control circuit in embodiment. Explanatory drawing of the operation | movement in an overinput control circuit. The example of the waveform of the signal in each part of the radio wave receiving apparatus in an embodiment. The modification of an overinput control circuit. 1 is a configuration diagram of a straight-type radio wave receiver. The example of a waveform of each signal in each part of the conventional electric wave receiver.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[Radio clock]
FIG. 1 is a block diagram showing a schematic configuration of a radio timepiece 1 according to the present embodiment. According to the figure, the radio timepiece 1 includes a CPU (Central Processing Unit) 100, an input unit 200, a display unit 300, a ROM (Read Only Memory) 400, a RAM (Random Access Memory) 500, and reception control. Unit 600, time code generation unit 700, timing circuit unit 800, and oscillation circuit unit 900. Each unit except for the oscillation circuit unit 900 is connected by a bus B, and the oscillation circuit unit 900 is connected to the time measuring circuit unit 800.

  The CPU 100 reads out a program stored in the ROM 400 in accordance with a predetermined timing or an operation signal input from the input unit 200, develops it in the RAM 500, and instructs each unit constituting the radio timepiece 1 based on the program. Perform data transfer. Specifically, for example, the reception control unit 600 is controlled at predetermined time intervals to execute standard radio wave reception processing, and the time measuring circuit unit 800 counts time based on the standard time code input from the time code generation unit 700. Correct the current time data.

  The input unit 200 includes switches for executing various functions of the radio timepiece 1, and outputs corresponding operation signals to the CPU 100 when these switches are operated. The display unit 300 is configured with a small liquid crystal display or the like, and displays the current time and the like based on a display signal input from the CPU 100.

  The ROM 400 stores system programs and application programs for the radio timepiece 1, programs and data for realizing the present embodiment, and the like. The RAM 500 is used as a work area for the CPU 100, and temporarily stores programs, data, and the like read from the ROM 400.

  The reception control unit 600 includes a radio wave receiving device 620. The radio wave receiver 620 cuts out unnecessary frequency components of the long wave standard radio wave received by the receiving antenna, extracts the corresponding frequency signal, reproduces the data signal, and outputs it to the time code generation unit 700.

  The time code generation unit 700 converts the data signal input from the radio wave receiver 620 into a digital signal, and generates a standard time code including data necessary for a clock function such as a standard time code, an integration code, and a day code. It outputs to CPU100.

  The clock circuit unit 800 counts the signal input from the oscillation circuit unit 900 to clock the current time, and outputs the current time data to the CPU 100. The oscillation circuit unit 900 always outputs a clock signal having a constant frequency.

[Radio wave receiver]
FIG. 2 is a block diagram showing a circuit configuration of the superheterodyne radio wave receiving device 620 according to this embodiment. According to the figure, the radio wave receiving device 620 includes a receiving antenna 621, an RF amplification circuit 622, a frequency conversion circuit 623, a local oscillation circuit 624, filter circuits 625 and 628, an enhancement circuit 626, and an IF amplification circuit. 627, a detection circuit 629, an AGC circuit 631, and an over-input control circuit 632.

  The reception antenna 621 is configured by, for example, a bar antenna, receives a long-wave standard radio wave having a predetermined frequency including a time code, converts the received long-wave standard radio wave into an electric signal, and outputs the electrical signal.

  The RF amplifier circuit 622 amplifies or attenuates the signal input from the receiving antenna 621 in accordance with the control signal input from the AGC circuit 631 and the control signal b input from the over-input control circuit 632, and the signal a And as a signal a1.

  The frequency conversion circuit 623 synthesizes the signal a1 input from the RF amplifier circuit 622 and the local oscillation frequency signal (local oscillation signal) input from the local oscillation circuit 624 to generate an intermediate frequency signal (intermediate frequency signal). Convert to and output. The local oscillation circuit 624 generates and outputs a local oscillation signal having a predetermined frequency.

  The filter circuit 625 is configured by a band pass filter (BPF) or the like, passes a signal in a predetermined frequency range with respect to the intermediate frequency signal input from the frequency conversion circuit 623, blocks a frequency component outside the range, Output as e.

  The enhancement circuit 626 amplifies the signal e input from the filter circuit 625 according to the control signal c input from the over-input control circuit 632, and outputs the amplified signal as a signal f.

  The IF amplifier circuit 627 amplifies (or attenuates) the signal input from the enhancement circuit 626 in accordance with the control signal input from the AGC circuit 631 and outputs the amplified signal. The filter circuit 628 is configured by a band pass filter or the like, and allows a signal in a predetermined frequency range to pass through the signal input from the IF amplifier circuit 627, and blocks and outputs out-of-range frequency components.

  The detection circuit 629 detects and outputs the signal input from the filter circuit 628. The detection signal output from the detection circuit 629 is input to the time code generation unit 700 as a reproduced data signal and used for correcting the current time.

  The AGC circuit 631 outputs a control signal for adjusting the amplification degrees of the RF amplifier circuit 622 and the IF amplifier circuit 627 in accordance with the level of the signal input from the filter circuit 628.

  The excessive input control circuit 632 controls the amplification level in the RF amplification circuit 622 according to the level of the signal a input from the RF amplification circuit 622, and the control signal that controls the amplification level in the enhancement circuit 626. c is generated and output.

[Over-input control circuit]
FIG. 3 is a block diagram showing a circuit configuration of the over-input control circuit 632. According to the figure, the overinput control circuit 632 includes an overinput detection circuit 6321, an RF amplification control circuit 6322, and an enhancement control circuit 6323.

  The excessive input detection circuit 6321 detects whether or not the level of the signal a input from the RF amplification circuit 622 exceeds the dynamic range (voltage level range) of the radio wave receiving device 620. And when it is judged that it exceeded, the signal according to the excess level of the signal a with respect to a dynamic range is output.

  Specifically, the over-input detection circuit 6321 has a comparison as a threshold for determining whether or not the level of the signal a input from the RF amplifier circuit 622 exceeds the dynamic range in the over-input detection circuit 6321. A voltage value (not shown) is stored, and when it is determined that the level of the signal a input from the RF amplifier circuit 622 exceeds the comparison voltage value, the level of the signal a with respect to the comparison voltage value is determined. Output the signal. The comparison voltage value does not necessarily need to be set to a dynamic range (voltage level range) that enables reception by the radio wave receiving device 620, and may be another value lower than the value of the dynamic range.

  The RF amplification control circuit 6322 generates a control signal b for controlling the amplification degree of the RF amplification circuit 622 in accordance with the signal input from the excessive input detection circuit 6321. Specifically, when the signal a does not exceed the comparison voltage value, the control signal b for maintaining the current amplification degree is output. When the signal a exceeds, the signal a does not exceed the comparison voltage value. A control signal b for reducing (attenuating) the amplification degree by an amount corresponding to the excess level of the signal a with respect to the comparison voltage value is output.

  The enhancement control circuit 6323 generates and outputs a control signal c that controls the amplification degree of the enhancement circuit 626 in accordance with the control signal b input from the RF amplification control circuit 6322. Specifically, the control signal c for increasing (amplifying) the amplification degree of the IF amplification circuit 627 by the amount corresponding to the attenuation amount of the amplification degree of the RF amplification circuit 622 by the control signal b is output.

  Here, specific control of the over-input control circuit 632 will be described. FIG. 4 is a diagram for explaining an example of control by the over-input control circuit 632. The horizontal axis represents the level of the signal a, and the vertical axis represents the amplification degree of the RF amplification circuit 622 and the amplification degree of the enhancement circuit 626. Show.

  When the level of the signal a does not exceed the comparison voltage value (within the range of the comparison voltage value in FIG. 4), the RF amplification control circuit 6322 generates a control signal b that maintains the current amplification degree of the RF amplification circuit 622. The control signal c for maintaining the current amplification degree of the enhancement circuit 626 is generated by the enhancement control circuit 6323. Therefore, the amplification degree of the RF amplifier circuit 622 is maintained at a constant value, for example, by the control of only the AGC circuit 631. Further, the amplification degree of the enhancement circuit 626 is maintained at a constant value “1”, for example.

  When the level of the signal a exceeds the comparison voltage value (excess range of the comparison voltage value in FIG. 4), the RF amplification control circuit 6322 decreases the amplification degree of the RF amplification circuit 622 in proportion to the increase of the signal a ( The control signal b to be attenuated) is generated, and the enhancement control circuit 6323 generates a control signal c to increase (amplify) the amplification degree of the enhancement circuit 626 by an amount equal to the attenuation amount of the amplification degree by the signal b. The Therefore, as the level of the signal a increases, the amplification degree of the RF amplification circuit 622 is gradually attenuated, and the amplification degree of the enhancement circuit 626 is substantially equal to the attenuation amount of the amplification degree of the RF amplification circuit 622. Increased (amplified).

[Circuit operation]
Next, the reception operation in the radio wave receiving device 620 will be described. FIG. 5 is a diagram for explaining a reception operation in the radio wave receiving device 620 and shows an example of each signal waveform in the radio wave receiving device 620. The following description will be made assuming that the value of the comparison voltage value stored in the over-input detection circuit 6321 is set to the dynamic range of the radio wave receiver 620.

  First, the signal d received by the receiving antenna 621 is a signal having the waveform shown in FIG. This received signal d is the same as the signal waveform shown in FIG. 8B in the above [Problem to be Solved by the Invention], and is a signal in which the amplitude of the transmitted signal greatly fluctuates due to mixed noise. Yes. The received signal d is amplified by the RF amplifier circuit 622 and output as signals a and a1.

  Then, in the excessive input control circuit 632, the excessive input detection circuit 6321 detects a signal portion exceeding the dynamic range of the signal a, that is, an excess level indicating how much the amplitude value of the signal a exceeds the dynamic range.

  Next, the RF amplification control circuit 6322 generates a control signal b that attenuates the amplification degree of the RF amplification circuit 622 according to the detected excess level, and the amplification degree of the RF amplification circuit 622 is attenuated according to the control signal b. The As a result, the signal a1 output from the RF amplifier circuit 622 becomes a signal having the waveform shown in FIG. That is, according to FIG. 7B, the signal a1 is a signal whose amplitude does not exceed the dynamic range because the amplitude of the signal portion exceeding the dynamic range of the signal d shown in FIG. Yes.

  Subsequently, the signal a1 is converted into an intermediate frequency signal (IF signal) by the frequency conversion circuit 623, passes through the filter circuit 625, and is output as the signal e. FIG. 5C is a diagram showing a signal waveform of the signal e output from the filter circuit 625. As shown in FIG. 9C, the signal e has a partial amplitude with respect to the original signal waveform of the envelope indicated by the dotted line in the figure due to the attenuation of the amplification degree in the RF amplifier circuit 622 according to the control signal b. The waveform is lowered. Further, the amount of decrease in the amplitude is in accordance with the attenuation amount of the amplification degree by the RF amplifier circuit 622.

  In the over-input control circuit 632, the enhancement control circuit 6323 generates and outputs a control signal c that increases (amplifies) the amplification degree of the enhancement circuit 626 in accordance with the signal b generated by the RF amplification control circuit 6322. The Then, the amplification degree of the enhancement circuit 626 is increased according to the control signal c. As a result, the signal f output from the enhancement circuit 626 has a waveform shown in FIG. As shown in FIG. 4D, the signal f is amplified (compensated) by the decrease in the amplitude of the signal e shown in FIG. 4C due to the increase in the amplification degree in the enhancement circuit 626 according to the control signal c. In addition, the original signal waveform is obtained.

  This signal e is amplified by the IF amplification circuit 627, detected by the detection circuit 629, and a detection signal is output. Therefore, the detection signal has a waveform that accurately reproduces the data signal included in the received standard radio wave.

[Action / Effect]
As described above, according to the present embodiment, in the radio wave receiver 620 of the radio timepiece 1, the signal a received by the reception antenna 621 and amplified by the RF amplifier circuit 622 by the over-input control circuit 632 is transmitted to the radio wave receiver 620. It is detected whether or not a dynamic range or a preset comparison voltage value is exceeded, and if it exceeds, the amplification degree of the RF amplifier circuit 622 is reduced (attenuated) according to the excess level, and the enhancement circuit 626 is increased. Is increased (amplified). For this reason, when the signal level of the received signal d at the receiving antenna 621 exceeds the dynamic range or the comparison voltage value due to noise mixing or the like, the data signal included in the signal portion exceeding the dynamic range is not cut. Accurate data signal reproduction is realized.

[Modification]
The embodiment to which the present invention is applicable is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit of the present invention.

(1) Over-input control circuit 632
For example, the overinput control circuit 632 in the embodiment may be configured as an overinput control circuit 632A shown in FIG. According to the figure, the overinput control circuit 632A includes an overinput detection circuit 6321, an RF amplification control circuit 6322, an enhancement control circuit 6323, and a delay circuit 6324.

  The delay circuit 6324 delays the signal c input from the enhancement control circuit 6323 by a predetermined time and outputs it. Here, in the radio wave receiver 620, the signal a output from the RF amplifier circuit 622 is delayed by passing through the frequency conversion circuit 623 and the filter circuit 625 until it is input to the enhancement circuit 626. In particular, the delay caused by passing through the filter circuit 625 is large. For this reason, by setting the degree of delay by the delay circuit 6324 according to the degree of delay of the filter circuit 625, the timing of attenuation in the RF amplifier circuit 622 and the timing of amplification in the enhancement circuit 626 can be adjusted. Therefore, more accurate data signal reproduction is realized.

(3) Radio wave receiving device 620
In the above-described embodiment, the superheterodyne radio wave receiver 620 is used, but a straight system may be used.

  FIG. 7 is a block diagram showing a circuit configuration of a straight-type radio wave receiver 620A to which the present invention is applied. According to the figure, the straight type radio wave receiver 620A includes a receiving antenna 621, an RF amplifier circuit 622, a filter circuit 633, an enhancement circuit 626, a detection circuit 634, and an over-input control circuit 632. Composed. In this case, the signal output from the enhancement circuit 626 is input to the detection circuit 634.

1 Radio clock 100 CPU
200 Input unit 300 Display unit 400 ROM
500 RAM
600 reception control unit 620 radio wave reception device 621 reception antenna 622 RF amplification circuit 623 frequency conversion circuit 624 oscillation circuit 625, 628 filter circuit 626 enhancement circuit 627 IF amplification circuit 629 detection circuit 631 AGC circuit 632 over-input control circuit 6321 over-input detection circuit 6322 RF amplification control circuit 6323 Enhancement control circuit 6324 Delay circuit 700 Time code generation unit 800 Timekeeping circuit unit 900 Oscillation circuit unit

Claims (9)

First amplification means for amplifying a received signal received by an antenna;
Filter means for extracting a signal in a predetermined frequency band from the reception signal amplified by the first amplification means;
Second amplification means for further amplifying the reception signal extracted by the filter means;
Level detection means for detecting whether the received signal amplified by the first amplification means is within a predetermined voltage level range;
When the level detection means detects that the received signal exceeds a predetermined voltage level range, the amplification in the first amplification means is attenuated and the amplification in the second amplification means is set. Over-input control means for controlling to increase;
Detecting means for detecting the received signal amplified by the second amplifying means;
A radio wave receiving apparatus comprising: A delay unit for delaying the control operation of the increase in the amplification degree in the second amplification unit;
The over-input control means attenuates the amplification degree in the first amplification means when the level detection means detects that the received signal exceeds a predetermined voltage level range, and the delay means The radio wave receiving apparatus according to claim 1, wherein control is performed so that the amplification degree of the second amplifying means is increased after being delayed.   The overinput control means continuously attenuates the amplification degree in the first amplification means when the level detection means detects that the received signal exceeds a predetermined voltage level range, 2. The radio wave receiving apparatus according to claim 1, wherein control is performed so that the amplification degree of the second amplifying means is continuously increased.   The over-input control unit attenuates the amplification degree in the first amplification unit stepwise when the level detection unit detects that the received signal exceeds a predetermined voltage level range; 2. The radio wave receiving apparatus according to claim 1, wherein control is performed so that the amplification degree of the second amplifying means is increased stepwise. A first amplifier circuit for amplifying a received signal received by an antenna;
A filter circuit for extracting a signal in a predetermined frequency band from the reception signal amplified by the first amplifier circuit;
A second amplification circuit for further amplifying the reception signal extracted by the filter circuit;
A level detection circuit for detecting whether or not the reception signal amplified by the first amplification circuit is within a predetermined voltage level range;
When the level detection circuit detects that the received signal exceeds a predetermined voltage level range, the amplification in the first amplification circuit is attenuated and the amplification in the second amplification circuit is increased. An over-input control circuit for controlling to increase,
A detection circuit for detecting the reception signal amplified by the second amplification circuit;
A radio wave receiving circuit comprising: A delay circuit for delaying the control operation for increasing the amplification degree in the second amplifier circuit;
The over-input control circuit is
When the level detection circuit detects that the received signal exceeds a predetermined voltage level range, the amplification level in the first amplification circuit is attenuated, and the delay circuit causes the second amplification circuit to be attenuated. The radio wave receiving circuit according to claim 5, wherein the amplification is controlled so as to increase after being delayed.   The over-input control circuit continuously attenuates the degree of amplification in the first amplifier circuit when the level detection circuit detects that the received signal exceeds a predetermined voltage level range, 6. The radio wave receiving circuit according to claim 5, wherein the second amplifying circuit is controlled so as to continuously increase an amplification factor.   When the level detection circuit detects that the received signal exceeds a predetermined voltage level range, the over-input control circuit attenuates the amplification degree in the first amplification circuit in stages. The radio wave receiving circuit according to claim 5, wherein the second amplification circuit is controlled to increase the amplification degree in a stepwise manner. A first amplifying means for amplifying a reception signal received by a standard radio wave including time information by an antenna;
Filter means for extracting a signal in a predetermined frequency band from the reception signal amplified by the first amplification means;
Second amplification means for further amplifying the reception signal extracted by the filter means;
Level detection means for detecting whether the received signal amplified by the first amplification means is within a predetermined voltage level range;
When the level detection means detects that the received signal exceeds a predetermined voltage level range, the amplification in the first amplification means is attenuated and the amplification in the second amplification means is set. Over-input control means for controlling to increase;
Detection output means for detecting the reception signal amplified by the second amplification means and outputting it as a detection signal;
Time code generating means for generating time information based on the detection signal output from the detection output means;
A time measuring means for measuring the current time;
Time correcting means for correcting the current time measured by the time measuring means based on the time information generated by the time code generating means;
A radio-controlled timepiece characterized by comprising:

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