JP2008196954A - Radio-controlled timepiece - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To properly perform tuning to a receiving standard radio wave signal even when transmission delay in a signal transmission path exists. <P>SOLUTION: A control means 13 controls delay means 10, 12 so that a phase of a first signal and a second signal are in the same phase by entering signals from a local oscillation means 7 to a phase comparison means 11 as each first signal and second signal through delay means 10, 12, referring an output signal of the phase comparison means 11 in a first state closing a tuning short circuit means 9, then, in a second state opening the tuning short circuit means 9, performs proper tuning by entering the signals from the local oscillation means 7 through the delay means 10, an antenna tuning means 1 and the delay means 12 as the first signal and the second signal to the phase comparison means 11, respectively, referring the output signal of the phase comparison means 11 and controlling tuning characteristics of the antenna tuning means 1 so that a phase difference between the first signal and the second signal is 90 degrees. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a radio timepiece that wirelessly receives a standard radio signal including a time code representing the current time and corrects the time based on the time code.

Conventionally, a radio timepiece that receives a standard radio signal including a time code representing the current time by radio and corrects the time inside the radio timepiece to a time corresponding to the time code has been used. Even when an error occurs in the timekeeping time of the radio-controlled timepiece itself, it is possible to correct the time based on the received time code and display it by correcting the time.
By the way, in order to properly receive a standard radio signal, a radio timepiece having a tuning circuit for accurately tuning to the frequency of the received standard radio signal has been developed (for example, see Patent Documents 1 and 2).

  Conventionally, when tuning the antenna of a radio clock receiver circuit, a capacitor with a capacitance value obtained from the antenna inductance value and the standard radio signal frequency is prepared during the assembly process, and the frequency of the standard radio signal input from the outside of the circuit is prepared. Or an external device that measures the output voltage of the antenna by electromagnetic coupling with the antenna is prepared as shown in Patent Document 1 The tuning frequency is adjusted with.

  However, there are two types of standard radio signal frequencies in Japan, and the frequency of standard radio signals varies from country to country. In the adjustment method, the adjustment must be made for each standard radio wave to be received (for example, 40 kHz, 60 kHz, 77.5 kHz, etc.), and in the case of a single circuit board and after the circuit board is incorporated in the housing Since there is a shift in frequency, there is a problem that adjustment must be performed in a state where the filter is incorporated in a housing, which is complicated. In particular, when the casing is a metal casing such as stainless steel, there is a problem that the tuning frequency shift is significant.

In order to solve this problem, the capacitor of the antenna tuning circuit is configured with a variable capacitor, or the switch configured with a field effect transistor (FET), bipolar transistor (TR), etc. and a plurality of capacitors are combined. Thus, the capacitance can be varied, a signal applied to the antenna tuning circuit is applied from the local oscillation means (LO means) of the receiving circuit, and the phase of the LO oscillation means signal and the output signal of the antenna tuning circuit are compared. Thus, a method for detecting the tuning has been proposed.
However, when comparing the phase of the signal, there is a problem that the phase of the signal is shifted due to stray capacitance existing in the signal transmission path, and the original tuning point is shifted. This phenomenon has a problem that the influence is particularly great in an antenna tuning circuit having a low Q value.

FIG. 2 is a basic configuration diagram of a general double balanced differential amplifier constituting the phase comparator.
In FIG. 2, transistors Q1 and Q2 and transistors Q3 and Q4 are differential amplifiers that amplify the LOOUT signal output from the local oscillation means. If the transistors Q1 and Q2 are antiphase amplifiers, the transistors Q3 and Q4 function as positive phase amplifiers.
The emitter sides of these differential amplifiers are connected to transistors Q5 and Q6, respectively, and transistors Q5 and Q6 also constitute a differential amplifier. When the ANTOUT signal input via the antenna is input to the transistors Q5 and Q6, the transistors Q5 and Q6 are alternately turned on and off alternately by the increase and decrease of the ANTOUT signal, thereby being connected to the collector side of the transistors Q5 and Q6. The two differential amplifier circuits are alternately turned on and off alternately. Thereby, the LOOUT signal and the ANTOUT signal are multiplied.

Now, LOOUT signal = sin (ωt + α)
ANTOUT signal = sin (ωt + β)
Then,
LOOUT signal × ANTOUT signal = (1/2) × cos (β−α) − (1/2) × cos (2ωt + α + β)
It becomes. The first term is a direct current (DC) component that is not related to frequency, the second term is an alternating current (AC) component, and if the second term is cut off by a suitable low-pass filter (LPF) 21, the phase comparator ( β−α), that is, a PHASE signal that is a DC component corresponding to the phase difference between the LOOUT signal and the ANTOUT signal is output.

FIG. 3 shows the DC output of the phase comparator (the PHASE signal) according to the phase difference between the LOOUT signal and the ANTOUT signal. According to this, 1 V is detected when the phase difference is 0 (360) degrees, 0 V when the phase difference is 90 (270) degrees, and -1 V when the phase difference is 180 degrees, and the DC output of the phase comparator is detected. It can be seen that the phase difference can be detected.
FIG. 4 is a phase change vs. frequency characteristic when the antenna Q value is changed, and FIG. 5 is a characteristic diagram showing a gain vs. frequency characteristic when the antenna Q value is changed, each having a tuning frequency of 40 kHz. It is an example.

In FIG. 5, it can be seen that the antenna of each Q value has a maximum point of gain at 40 kHz and shows tuning at 40 kHz.
In FIG. 4, the phase change at 40 kHz differs depending on the Q value, and with a high Q value (Q = 25, 50, 100), the frequency at which the phase difference is 90 degrees is approximately 40 kHz, but the low Q value ( In Q = 13, 6, 3), the frequency at which the phase difference is 90 degrees is lower than 40 kHz, and the tuning detection by the phase detection is different from the original tuning frequency.

In FIG. 2, the collectors of the transistors Q1 to Q6 have a parasitic capacitance with the substrate (substrate) due to the transistor structure, and the phase of the LOOUT signal and the ANTOUT signal is affected by this parasitic capacitance. . This is similarly affected by the parasitic capacitance existing in the transmission path of the LOOUT signal and the ANTOUT signal.
FIG. 6 and FIG. 7 show the effects when a delay occurs in the signal due to the parasitic capacitance.

  6 shows the case where the Q value = 100, and FIG. 7 shows the case where the Q value = 12. In the case of Q value = 100, even if there is a transmission delay in the two signals input to the phase comparator, there is almost no effect. Therefore, if 90 degrees is detected by the phase comparator, tuning can be determined. However, in the case of Q = 12 in FIG. 7, when there is a transmission delay, the point at which the phase is 90 degrees with respect to the original tuning frequency of 40 kHz is lower by about 500 Hz. As a result, there is a problem that the tuning frequency to be detected shifts in the tuning detection by the phase comparator.

Japanese Patent Laying-Open No. 2005-130055 (paragraphs [0041] to [0080], FIGS. 1 to 7) WO 2004/105240 (page 7, line 20 to page 17, line 28, FIGS. 1 to 4)

  An object of the present invention is to enable proper tuning of a received standard radio signal even when there is a transmission delay in a signal transmission path.

  According to the present invention, the antenna tuning means for receiving a standard radio signal including a time code representing the current time with a variable tuning frequency, the local oscillation means, and the signal from the antenna tuning means for the local oscillation A frequency converting means for converting the frequency by a signal from the means, a time code detecting means for detecting the time code based on the signal from the frequency converting means, a time measuring means for measuring the time, and the time measuring means Controlling the phase difference between the first signal from the local oscillating means and the second signal from the output of the antenna tuning means; And a tuning control means for controlling a tuning characteristic of the antenna tuning means with respect to the standard radio signal. Meter is provided.

  The tuning control unit controls the tuning characteristic of the antenna tuning unit with respect to the standard radio signal by controlling the phase difference between the first signal from the local oscillation unit side and the second signal from the output side of the antenna tuning unit. The standard radio signal is received by the antenna tuning means for which the tuning characteristics are set, and the time correcting means corrects the time measured by the time measuring means at a time corresponding to the time code included in the standard radio signal.

  Here, the tuning control means has a first input unit and a second input unit, and the level of the first signal input to the first input unit and the second signal input to the second input unit. Phase comparison means for outputting a third signal corresponding to the phase difference; and the first signal and the second signal before the first signal and the second signal are input to the first input portion and the second input portion, respectively. A delay means for delaying at least one; a switch means provided in parallel with the antenna tuning means; and a control means, the control means in the first state where the switch means is closed, Is input to the first input unit as the first signal, and the output signal of the local oscillation unit is input to the second signal as the second signal from the output unit side of the antenna tuning unit via the switch unit. Input to the input section, the phase ratio In the second state in which the switch means is opened after controlling the delay means so that the phase of the first signal and the second signal has a predetermined phase relationship with reference to the third signal from the means, A signal from the oscillating means side is input to the first input section as the first signal, and an output signal of the local oscillating means is input from the output section side of the antenna tuning means via the antenna tuning means to the second signal. The tuning characteristics of the antenna tuning means are set so that the phases of the first signal and the second signal have a predetermined phase relationship with reference to the third signal from the phase comparison means. You may comprise so that it may control.

The control means controls the delay means so that the phases of the first signal and the second signal are in phase in the first state, and the first signal and the second signal in the second state. You may comprise so that the tuning characteristic of the said antenna tuning means may be controlled so that a phase difference may be 90 degree | times.
The phase comparison unit may include a double balanced differential amplifier, and may be configured to output the third signal corresponding to the phase difference between the first signal and the second signal.

  The delay means delays a signal from the local oscillation means side and inputs the first signal and a first delay means for input to the first input section, and a signal from the output section side of the antenna tuning means. Second delay means for delaying and inputting the second signal as the second signal to the second input section, wherein the control means refers to the third signal in the first state and refers to the first delay means. The first signal and the second signal may be controlled to have the same phase by controlling the delay amount of at least one of the second delay means.

  The antenna tuning means includes variable capacitance means for changing tuning characteristics, and the control means changes the capacitance of the variable capacitance means in the second state to change the third signal. The tuning characteristics of the antenna tuning means may be controlled so that the phase difference between the first signal and the second signal is 90 degrees with reference to FIG.

And a storage means for storing the delay amount of the delay means, storing the delay amount of the delay means set in the first state in the storage means, and then tuning the antenna tuning means in the second state. When controlling the characteristics, instead of the operation in the first state, the delay amount of the delay means may be set to the delay amount stored in the storage means.
Further, at least the antenna tuning means may be configured to be disposed in a metal casing.

  The radio timepiece according to the present invention makes it possible to properly tune a received standard radio signal even when there is a transmission delay in the signal transmission path.

FIG. 1 is a block diagram of a radio timepiece according to an embodiment of the present invention.
In FIG. 1, a radio timepiece includes an antenna tuning means 1 that receives and outputs a standard radio signal, an automatic gain control (AGC) amplification means 2 that amplifies a signal from the antenna tuning means 1, a local oscillation means 7, and an AGC amplification means 2 The frequency conversion means 3 converts the frequency of the signal from the signal to the intermediate frequency by the signal from the local oscillation means 7 and outputs it, the intermediate frequency amplification means 4 that amplifies the signal from the frequency conversion means 3, and the signal from the intermediate frequency amplification means 4 The AGC control means 6 for controlling the gain of the AGC amplifying means 2 according to the output signal level of the detecting means 5 is provided.

  The radio timepiece has a first input unit and a second input unit, and a signal (first signal) input to the first input unit and a signal (second signal) input to the second input unit. The phase comparison means 11 for outputting a DC signal (third signal) having a voltage level corresponding to the phase difference between the local oscillation means 7 and the local oscillation signal from the local oscillation means 7 is delayed as the first signal of the first phase comparison means 11. Delay means 10 for inputting to the input section; delay means 12 for delaying a signal from the output section side of the antenna tuning means 1 and inputting the second signal to the second input section of the phase comparison means 11; and antenna tuning means 1 And a tuning short-circuit means 9 provided in parallel.

  In addition, the radio timepiece includes a control unit 13 and a control unit 13 that perform processing to be described later and control each component of the radio timepiece by executing a program configured by a central processing unit (CPU) and stored in the storage unit 14. Storage means 14 for storing programs to be executed and data, input means 15 constituted by operation buttons, display means 16 constituted by a liquid crystal display (LCD), oscillation means 18 for outputting a signal of a predetermined frequency, transmission Frequency dividing means 17 is provided for dividing the signal from the means 18 and outputting a clock signal as a reference for the time measuring operation.

Although not shown, the antenna tuning means 1 includes an antenna coil and a variable capacitor (for example, a varicap or a capacitor circuit that is configured by a plurality of switches and a plurality of capacitors and whose capacitance value can be changed by switching the switches). And has a function of wirelessly receiving a standard radio wave signal including a time code indicating the current time and having a variable tuning frequency.
The tuning short-circuit means 9 is an open / close switch composed of a transistor or the like. The tuning short-circuit means 9 is in a closed state (ie, a state in which both ends of the antenna tuning means 1 are short-circuited) and an open state under the control of the control means 13. It is configured to selectively take any one of the second states.

The delay means 10 and 12 are delay means whose delay amounts can be changed by the control means 13, and each of the delay means 10 and 12 delays their input signals by a set delay amount to obtain the first signal, The second signal is input to the first input unit and the second input unit of the phase comparison unit 11.
The phase comparison unit 11 is a phase comparator having the double balanced differential amplifier shown in FIG. 2, and the first signal input to the first input unit via the delay unit 10 and the delay unit 12 are used. The DC signal (third signal) having a voltage level corresponding to the phase difference from the second signal input to the second input unit is output to the control means 13.

Here, the antenna tuning means 1, the tuning short-circuit means 9, the delay means 10 and 12 and the phase comparison means 11 constitute a tuning detection control means 8.
The tuning short-circuit means 9, the delay means 10, 12, the phase comparison means 11 and the control means 13 constitute a tuning control means.
The delay means 10 constitutes a first delay means, and the delay means 12 constitutes a second delay means.
The control means 13 constitutes a time measuring means for performing a time measuring operation by counting a clock signal from the frequency dividing means 17, and a time adjusting means for correcting the time measured by the time measuring means to a time corresponding to the time code. ing.
The detection means 5 and the control means 13 constitute time code detection means.

In the radio timepiece configured as described above, the operation of receiving the standard radio signal and correcting the time measured by the control means 13 to the time corresponding to the time code included in the standard radio signal is illustrated in FIG. The outline will be described with reference to FIG.
The frequency dividing means 17 divides the signal of a predetermined frequency from the oscillating means 18 and outputs a clock signal that serves as a reference for time measuring operation. The control means 13 counts the clock signal from the frequency dividing means 17 to perform a time measuring operation (at this time, the control means 13 functions as a time measuring means), and displays a display control signal corresponding to the time counting to the display means 16. (At this time, the control means 13 functions as a control means.) The display means 16 displays the time corresponding to the display control signal from the control means 13.

When the time code included in the standard radio wave signal is received and the time is adjusted, the control unit 13 receives a predetermined time for automatically adjusting the time or when a predetermined operation is performed by the input unit 15. In addition, by turning on the power of the tuning detection means 8, the AGC amplification means 2, the frequency conversion means 3, the intermediate frequency amplification means 4, the detection means 5, the AGC control means 6 and the local oscillation means 7, the standard radio wave signal reception operation is performed. I do.
The tuning detection control means 8 and the control means 13 operate so that the antenna tuning means 1 accurately tunes to the frequency of the received standard radio wave signal as will be described later.

  The antenna tuning means 1 receives and outputs a standard radio signal. The AGC amplification unit 2 amplifies the signal from the antenna tuning unit 1 and outputs it. The frequency converting means 3 converts the signal from the AGC amplifying means 2 into an intermediate frequency signal by the signal from the local oscillating means 7 and outputs it. The intermediate frequency amplifying unit 4 amplifies and outputs the signal from the frequency converting unit 3. The detection means 6 detects the signal from the intermediate frequency amplification means 4 and outputs the time code obtained thereby to the control means 13. The AGC control means 6 controls the gain of the AGC amplification means 2 according to the output signal level of the detection means 5.

  The control means 13 corrects the time counted by itself to the time corresponding to the time code (at this time, the control means 13 functions as the time correction means), and displays a display control signal representing the time. 16 is output. The display means 16 displays the time corresponding to the display control signal. As a result, the correct current time corresponding to the received time code is displayed on the display means 16.

  Next, a tuning characteristic control process for optimizing the tuning characteristic of the antenna tuning means 1 for the standard radio signal will be described. The tuning characteristic control process includes a transmission delay correction process for correcting a signal transmission delay due to the stray capacitance of the signal transmission path and a tuning adjustment process for adjusting the tuning of the antenna tuning means 1. In this way, the transmission delay correction is performed so that it can be accurately determined whether or not the antenna tuning means 1 is tuned so that the antenna tuning means 1 does not deviate from the optimum tuning point due to the transmission delay in the signal transmission path. After that, tuning control of the antenna tuning means 1 is performed.

First, transmission delay correction processing for correcting signal transmission delay due to stray capacitance in the signal transmission path will be described.
In this case, the control means 13 first closes the tuning short-circuit means 9 (first state). Next, the control unit 13 causes the local oscillation unit 7 to output a carrier frequency signal of a standard radio wave signal to be tuned. The carrier frequency signal of the standard radio wave signal is input to the first input unit of the phase comparison unit 11 via the delay unit 10. This signal is referred to as a LOOUT signal (first signal).

At the same time, the carrier frequency signal of the standard radio signal is input from the output side of the antenna tuning unit 1 to the second input unit of the phase comparison unit 11 via the delay unit 12 via the tuning short-circuit unit 9. This signal is referred to as an ANTOUT signal (second signal).
The phase comparison unit 11 outputs a PHASE signal (third signal), which is a DC signal having a voltage level corresponding to the phase difference between the LOOUT signal and the ANTOUT signal, to the control unit 13.

  Based on the PHASE signal, the control unit 13 controls the delay amount of at least one of the delay unit 10 and the delay unit 12 so that the LOOUT signal and the ANTOUT signal input from the delay units 10 and 12 are in phase. To do. For example, when the delay of the ANTOUT signal is larger than the LOOUT signal, the delay amount of the delay means 10 is increased to delay the LOOUT signal.

Now, when the first signal and the second signal having the same phase are input to the first input unit and the second input unit of the phase comparison unit 11, the output of the phase comparison unit 11 is the phase difference 0 of FIG. Phase detection signal (PHASE signal) at this time, and the phase detection signal at this time should be the maximum value.
Here, when the control means 13 delayed the LOOUT signal by changing the capacitance of the capacitor of the delay means 10, the PHASE signal shown in FIG. 3 was obtained before changing the capacitance value of the capacitor. If it is obtained larger than the PHASE signal, the ANTOUT signal is delayed due to the delay of the signal transmission path and the ANTOUT signal and the LOOUT signal are not in-phase signals before the capacitor capacity of the delay means 10 is changed. It will be.

On the other hand, when the obtained PHASE is smaller than before the capacitor capacity change, the control means 13 changes the capacitor of the delay means 12. In this way, the control means 13 changes the phase of at least one of the ANTOUT signal and the LOOUT signal by varying the capacitance of at least one of the delay means 10 and the delay means 12, and the phase detection signal of FIG. Is controlled to be maximum.
Thus, the delay means 10 and 12 are set so that the phase detection signal becomes maximum when the in-phase signal is input to the phase comparison means 11. Therefore, signal delay due to stray capacitance in the signal transmission path of the LOOUT signal and the ANTOUT signal is corrected.

Next, a tuning adjustment process for adjusting the tuning of the antenna tuning means 1 will be described.
First, the control means 13 opens the tuning short-circuit means 9 (second state), and then outputs a carrier frequency signal of a standard radio wave signal to be tuned from the local oscillation means 7, and the input side of the antenna tuning means 1. To enter.
Next, the control means 13 controls a variable capacitor (not shown) of the antenna tuning means 1, and the phase detection signal (PHASE signal; third signal) of the phase comparison means 11 is the maximum value shown in FIG. Then, the capacitance value of the capacitor of the antenna tuning means 1 is changed so that the phase difference between the ANTOUT signal and the LOOUT signal is 90 degrees. Thus, the tuning adjustment process is completed.

As described above, the tuning characteristic control process for optimizing the tuning characteristic of the antenna tuning means 1 for the standard radio signal is completed. In this way, by performing the transmission delay correction process and the tuning adjustment process based on the PHASE signal output from the phase comparison unit 11, the antenna tuning unit 1 is appropriately tuned to the frequency of the received standard radio signal. It becomes possible.
The transmission delay correction process before the tuning adjustment process may be performed each time a standard radio wave signal is received, and the delay amounts of the delay means 10 and 12 at the time of the transmission line delay process are stored in the storage means 14. In the subsequent reception operation, if the delay amount stored in the storage unit 14 is used, the transmission line delay process needs to be performed only once.

That is, when the delay amounts of the delay means 10 and 12 are set with the tuning short-circuit means 9 closed (first state) as described above, the delay amounts of the delay means 10 and 12 at that time are stored in the storage means 14. When the tuning characteristics of the antenna tuning means 1 are controlled after the tuning short-circuit means 9 is opened (second state), the delay amounts of the delay means 10 and 12 are set in place of the operation in the first state. The delay amount stored in the storage unit 14 may be set.
In addition, in the transmission delay correction process, the in-phase signal is input to the phase comparison unit 11, the delay amount of the delay units 10 and 12 is adjusted, and the delay unit is set so as to eliminate the phase difference between the LOOUT signal and the ANTOUT signal. Alternatively, the phase difference between the LOOUT signal and the ANTOUT signal may be detected, and the adjustment value of the antenna tuning means 1 may be adjusted in consideration of this phase difference.

  As described above, according to the radio-controlled timepiece according to the present embodiment, in the tuning detection by phase comparison, the delay means 10 is set so that the two signals input to the phase comparison means 11 have a predetermined phase relationship. 12, because the antenna tuning means 1 is controlled, the signal transmission delay due to the stray capacitance of the signal transmission path can be corrected, so that the accuracy of tuning detection by phase comparison can be improved. Can be accurately tuned to the frequency of the received standard radio signal.

Further, even when the antenna Q value is low, it is possible to tune accurately.
In addition, when at least the antenna tuning means 1 is housed in a metal (for example, stainless steel, titanium) housing, the Q value of the antenna is lowered. Even in such a case, the frequency of the received standard radio signal is reduced. It is possible to tune precisely.
Moreover, it is applicable not only to a digital radio timepiece but also to an analog radio timepiece.
Further, the present invention can be applied not only to radio clocks used in Japan but also to radio clocks used in other countries and multiple countries.

  The present invention is applicable to analog radio clocks and digital radio clocks used in a plurality of regions using standard radio signals for time correction such as Japan and the United States.

1 is a block diagram of a radio timepiece according to an embodiment of the present invention. It is a circuit diagram of the general phase comparison means used for embodiment of this invention. It is a characteristic view for demonstrating operation | movement of a phase comparison means. It is a characteristic view for demonstrating operation | movement of a phase comparison means. It is a characteristic view for demonstrating operation | movement of a phase comparison means. It is a characteristic view for demonstrating operation | movement of a phase comparison means. It is a characteristic view for demonstrating operation | movement of a phase comparison means.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Antenna tuning means 2 ... AGC amplification means 3 ... Frequency conversion means 4 ... Intermediate frequency amplification means 5 ... Detection means 6 constituting A time code detection means ... AGC control means 7 ... Local oscillation means 8 ... Tuning detection control means 9 ... Tuning short-circuit output means 10 constituting tuning control means ... Delay means 11 constituting first delay means and tuning control means ... Tuning Phase comparison means 12 constituting control means ... Delay means 13 constituting second delay means and tuning control means ... Control means 14 constituting time measuring means, time correcting means, time code detecting means and tuning control means ... Storage means 15 ... Input means 16 ... Display means 17 ... Division means 18 ... Oscillation means 21 ... Low-pass filter

Claims (8)

  Antenna tuning means for wirelessly receiving a standard radio wave signal including a time code representing the current time while the tuning frequency is variable, a local oscillation means, and a signal from the antenna tuning means by a frequency from the signal from the local oscillation means Frequency converting means for converting, time code detecting means for detecting the time code based on a signal from the frequency converting means, time measuring means for measuring time, and time time being measured by the time measuring means Time correction means for correcting the time to the time corresponding to the above-mentioned standard radio wave signal by controlling the phase difference between the first signal from the local oscillation means side and the second signal from the output side of the antenna tuning means And a tuning control means for controlling tuning characteristics of the antenna tuning means. The tuning control unit has a first input unit and a second input unit, and is responsive to a phase difference between the first signal input to the first input unit and the second signal input to the second input unit. Phase comparison means for outputting a third signal, and at least one of the first signal and the second signal before the first signal and the second signal are input to the first input portion and the second input portion, respectively. Delay means for delaying, switch means provided in parallel with the antenna tuning means, and control means,
The control means includes
In the first state in which the switch means is closed, a signal from the local oscillator means side is input as the first signal to the first input section, and an output signal of the local oscillator means is input via the switch means. The second signal is input to the second input unit as the second signal from the output side of the antenna tuning unit, and the phase of the first signal and the second signal is a predetermined phase relationship with reference to the third signal from the phase comparison unit After controlling the delay means to become
In the second state in which the switch means is opened, a signal from the local oscillating means side is input to the first input section as the first signal, and an output signal of the local oscillating means is passed through the antenna tuning means. The second signal is input to the second input unit as the second signal from the output side of the antenna tuning unit, and the phase of the first signal and the second signal is a predetermined phase with reference to the third signal from the phase comparison unit The radio timepiece according to claim 1, wherein the tuning characteristics of the antenna tuning means are controlled so as to be in a relation.   The control means controls the delay means so that the phases of the first signal and the second signal are in phase in the first state, and the phase difference between the first signal and the second signal in the second state. The radio timepiece according to claim 2, wherein the tuning characteristic of the antenna tuning means is controlled so that the angle becomes 90 degrees.   4. The phase comparison unit includes a double balanced differential amplifier, and outputs the third signal corresponding to a phase difference between the first signal and the second signal. The radio wave clock described. The delay means delays a signal from the local oscillating means side and delays the first signal and the first delay means for inputting to the first input section and the signal from the output section side of the antenna tuning means. And second delay means for inputting the second signal to the second input unit,
In the first state, the control means refers to the third signal and controls a delay amount of at least one of the first delay means and the second delay means, thereby controlling the first signal and the second signal. The radio timepiece according to any one of claims 2 to 4, wherein the phase is controlled so as to be in phase. The antenna tuning means comprises variable capacitance means for changing tuning characteristics,
In the second state, the control means changes the capacity of the variable capacity means so that the phase difference between the first signal and the second signal becomes 90 degrees with reference to the third signal. 6. The radio timepiece according to claim 2, wherein tuning characteristics of the tuning means are controlled.   Storage means for storing the delay amount of the delay means; storing the delay amount of the delay means set in the first state in the storage means; and thereafter, tuning characteristics of the antenna tuning means in the second state. 7. When controlling, the delay amount of the delay means is set to the delay amount stored in the storage means instead of the operation in the first state. Radio clock.   The radio timepiece according to any one of claims 1 to 7, wherein at least the antenna tuning means is disposed in a metal casing.

Images