Shift control circuit and wireless device

Patent metadata

Field	Value
Publication number	US-10165241-B2
Application number	US-201715692742-A
Country	US
Kind code	B2
Filing date	Aug 31, 2017
Priority date	Sep 27, 2016
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

A shift control circuit includes a first limiter circuit, a phase shifter, a first suppressor, and a reducer. The first limiter circuit limits the amplitude of a control target signal input from a microphone, having undergone A-D conversion by an A-D convener, and frequency differentiation by a pre-emphasis circuit, and having the relative intensity of harmonic components increased. The phase shifter performs, for the control target signal having undergone the amplitude limitation, phase shift on the frequency component within a first frequency range. The first suppressor suppresses, for the control target signal having undergone the phase shift, the frequency component equal to or greater than a second threshold. The reducer suppresses, for the control target signal having the suppressed frequency component, the frequency component within a second frequency range, and outputs as an information signal. A modulator performs frequency modulation on a carrier wave in accordance with the information signal, and a transmitter produces a transmission signal from the carrier wave having undergone the frequency modulation, and transmits the transmission signal via an antenna.

First claim

What is claimed is:

1. A shift control circuit provided in a wireless device that performs frequency modulation, and outputting an information signal to be applied to the frequency modulation, the shift control circuit comprising:
a first limiter circuit that limits an amplitude of an input control target signal to be equal to or less than a first threshold;
a phase shifter that shifts, for the control target signal having the amplitude limited by the first limiter circuit to be equal to or less than the first threshold, a phase of a frequency component within a predetermined first frequency range by a predetermined amount;
a first suppressor that suppresses, for the control target signal phase-shifted by the phase shifter, the frequency component equal to or greater than a second threshold; and
a reducer that suppresses, for any of (i) the control target signal having the amplitude limited by the first limiter circuit to be equal to or less than the first threshold, (ii) the control target signal phase-shifted by the phase shifter, and (iii) the control target signal having the frequency component equal to or greater than the second threshold and suppressed by the first suppressor, a frequency component within a predetermined second frequency range, and thus reducing a wave height value of the information signal,
wherein the shift control circuit outputs the information signal that is the control target signal having the frequency component equal to or greater than the second threshold and suppressed by the first suppressor or the control target signal having the frequency component within the second frequency range and suppressed by the reducer.

2. The shift control circuit according to claim 1 , wherein:
the reducer comprises:
a second limiter circuit that limits, for the control target signal having the frequency component equal to or greater than the second threshold and suppressed by the first suppressor, the amplitude to be equal to or less than a third threshold; and
a second suppressor that suppresses, for the control target signal having the amplitude limited by the second limiter circuit to be equal to or less than the third threshold, the frequency component equal to or greater than a fourth threshold, and
the shift control circuit outputs the information signal that is the control target signal having the frequency component equal to or greater than the fourth threshold and suppressed by the second suppressor.

3. The shift control circuit according to claim 2 , wherein the third threshold is greater than the first threshold.

4. The shift control circuit according to claim 2 , wherein the fourth threshold is regarded as being consistent with the second threshold.

5. The shift control circuit according to claim 3 , wherein the fourth threshold is regarded as being consistent with the second threshold.

6. The shift control circuit according to claim 1 , wherein:
the second frequency range is a frequency range equal to or less than a fifth threshold;
the reducer suppresses, for the control target signal having the amplitude limited by the first limiter circuit to be equal to or less than the first threshold, a frequency component equal to or less than the fifth threshold;
the phase shifter performs phase shift on the control target signal having the amplitude limited by the first limiter circuit to be equal to or less than the first threshold, and having the frequency component equal to or less than the fifth threshold and suppressed by the reducer; and
the shift control circuit outputs the information signal that is the control target signal having the frequency component equal to or greater than the second threshold and suppressed by the first suppressor.

7. The shift control circuit according to claim 1 , wherein:
the second frequency range is a frequency range equal to or less than a sixth threshold;
the reducer suppresses, for the control target signal phase-shifted by the phase shifter, the frequency component equal to or less than the sixth threshold;
the first suppressor suppresses, for the control target signal phase-shifted by the phase shifter and having the frequency component equal to Of less than the sixth threshold and suppressed by the reducer, the frequency component equal to or greater than the second threshold; and
the shift control circuit outputs the information signal that is the control target signal having the frequency component equal to or greater than the second threshold and suppressed by the first suppressor.

8. A wireless device comprising:
a shift control circuit that outputs an information signal to be applied to frequency modulation;
a modulator that performs frequency modulation of changing a frequency of a carrier wave in accordance with a signal level of the information signal; and
a transmitter that produces a transmission signal from the carrier wave frequency-modulated by the modulator, and transmits the produced signal via an antenna,
wherein:
the shift control circuit comprises:
a first limiter circuit that limits an amplitude of an input control target signal to be equal to or less than a first threshold;
a phase shifter that shifts, for the control target signal having the amplitude limited by the first limiter circuit to be equal to or less than the first threshold, a phase of a frequency component within a predetermined first frequency range by a predetermined amount;
a first suppressor that suppresses, for the control target signal phase-shifted by the phase shifter, the frequency component equal to or greater than a second threshold; and
a reducer that suppresses, for any of (i) the control target signal having the amplitude limited by the first limiter circuit to be equal to or less than the first threshold, (ii) the control target signal phase-shifted by the phase shifter, and (iii) the control target signal having the frequency component equal to or greater than the second threshold and suppressed by the first suppressor, a frequency component within a predetermined second frequency range, and thus reducing a wave height value of the information signal, and
the shift control circuit outputs the information signal that is the control target signal having the frequency component equal to or greater than the second threshold and suppressed by the first suppressor or the control target signal having the frequency component within the second frequency range and suppressed by the reducer.

9. The wireless device according to claim 8 , wherein:
the reducer comprises:
a second limiter circuit that limits, for the control target signal having the frequency component equal to or greater than the second threshold and suppressed by the first suppressor, the amplitude to be equal to or less than a third threshold; and
a second suppressor that suppresses, for the control target signal having the amplitude limited to be equal to or less than the third threshold by the second limiter circuit, the frequency component equal to or greater than a fourth threshold, and
the shift control circuit outputs the information signal that is the control target signal having the frequency component equal to or greater than the fourth threshold and suppressed by the second suppressor.

10. The wireless device according to claim 9 , wherein the third threshold is greater than the first threshold.

11. The wireless device according to claim 9 , wherein the fourth threshold is regarded as being consistent with the second threshold.

12. The wireless device according to claim 10 , wherein the fourth threshold is regarded as being consistent with the second threshold.

13. The wireless device according to

Assignees

• Icom Inc

Inventors

• Ueno Yasuo

Classifications

• H03G11/00

  Limiting amplitude; Limiting rate of change of amplitude · CPC title

• H03K5/131

  Digitally controlled · CPC title

• G06F1/10

  Distribution of clock signals {, e.g. skew} · CPC title

• H04L27/16

  Frequency regulation arrangements · CPC title

• H04N9/66 Primary

  for synchronous demodulators · CPC title