Radio wave receiving apparatus, radio wave receiving circuit and radio wave timepiece

Abstract

In the radio-wave receiving apparatus according to the invention, a signal received by a receiving antenna (621) is amplified and the amplified received signal is input into a multi-stage frequency conversion circuit (623) including a plurality of basic circuits (624n) connected in series. The multi-stage frequency conversion circuit (625) converts the frequency of the received signal from the antenna into frequencies based on signals (gn) input from the frequency divider circuit sequentially, thereby to output a signal ''a'' which is obtained by conversions into gradually lower frequencies. Detection is performed by a detection circuit (626) on the basis of the signal. Thereby, a radio-wave receiving apparatus which requires no local oscillating circuit nor a PLL circuit and is also stable in operation and high in accuracy is realized.

Description

[0001] References to related applications [0002] This application is based on, and claims priority from, prior Japanese Patent Applications No. 2005-217469 (filed on July 27, 2005) and No. 2005-345640 (filed on November 30, 2005), the entire contents of which are incorporated herein by reference Here for reference. technical field [0003] The present invention relates to, for example, a radio wave receiving device for receiving standard radio waves, a radio wave receiving circuit, and a radio wave watch. Background technique [0004] At present, in various countries (such as Japan, Germany, the United Kingdom, Switzerland, etc.), long-wave standard radio waves with time data, that is, time codes (time codes) added thereto are transmitted. In Japan, two transmitting stations in Fukushima and Saga prefectures transmit long-wave standard radio waves of 40 kHz and 60 kHz in which amplitude modulation is performed on a time code using a format of long-wave standard radio wave...

AI Technical Summary

Problems solved by technology

That is, (1) When a plurality of oscillation circuits corresponding to the frequency of the standard radio wave to be received are provided, the circuit scale of the radio wave receiving device becomes large, which increases the cost and limits the frequency of the standard radio wave that can be received. The problem

In addition, in the case of having a local oscillation circuit as in (2), the local oscillation circuit is constituted by, for example, a PLL (Phase Locked Loop) circuit having a VCO (Voltage Controlled Oscillator). However, in the PLL circuit, there is a problem that from It takes time for the power supply to be turned on until the operation is stable, and the oscillation frequency output from the VCO is unstable depending on the setting of the reference frequency

[0009] In addition, in the case of (3) dividing the reference frequency signal for timing to form a local oscillation signal, the divided signal does not exactly match the frequency required for converting the frequency of the received signal into an intermediate frequency. The problem of not being able to perform correct detection due to frequency deviation

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