Wireless receiver

Patent metadata

Field	Value
Publication number	US-9793934-B2
Application number	US-201615295254-A
Country	US
Kind code	B2
Filing date	Oct 17, 2016
Priority date	Oct 19, 2015
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

Abstract

A wireless receiver includes an RF muting circuit that opens and closes a signal line of a demodulated signal according to a received carrier strength level, a noise muting circuit that opens and closes the signal line according to a noise level in the modulated signal, and an RF attenuation circuit that attenuates a RF signal handled in a RF amplifier circuit, and additionally includes a reception mode switching circuit which can simultaneously select at least any two values from those comprising one of a plurality of predetermined threshold values of the RF muting circuit, one of a plurality of predetermined threshold values of the noise muting circuit and one of a plurality of predetermined amount of attenuation of the RF attenuation circuits. This configuration allows to provide a wireless receiver having a stable reception characteristics without sound interruption or interferences in a multi-wave operation of wireless microphones.

First claim

What is claimed is:

1. A wireless receiver comprising:
an RF muting circuit that opens and closes a signal line of a demodulated signal according to a carrier strength level of a received RF signal;
a noise muting circuit that opens and closes the signal line of a demodulated signal according to a noise level in the demodulated signal;
an RF signal attenuation circuit that attenuates a level of the RF signal that is handled in an RF amplifier circuit; and
a reception mode switching unit capable of simultaneously selecting at least any two values from those comprising one of a plurality of predetermined operating levels in the RF muting circuit, one of a plurality of predetermined operating levels in the noise muting circuit, and one of a plurality of predetermined amounts of attenuation in the RF signal attenuation circuit,
wherein by using the reception mode switching unit, the operating level of the RF muting circuit is lowered and the operating level of the noise muting circuit is raised, and the amount of attenuation in the RF signal attenuation circuit is increased at a time of multi-wave operation in which multiple transmitters are used in a predetermined area in contrast with a time of normal operation in which a single transmitter is used in the predetermined area.

2. The wireless receiver according to claim 1 , wherein the reception mode switching unit is configured to select the operating levels of the RF muting circuit, the operating levels of the noise muting circuit, and the amounts of attenuation in the RF signal attenuation circuit, in multiple steps of two or more.

3. The wireless receiver according to claim 1 , wherein a transmitter is a wireless microphone, and the wireless receiver receives a transmission signal from the wireless microphone and generates a demodulated signal.

4. The wireless receiver according to claim 1 , wherein the RF signal attenuation circuit is an RF signal attenuator connected to an input side of the RF amplifier circuit.

5. The wireless receiver according to claim 1 , wherein the RF signal attenuation circuit includes a gain adjustment circuit that adjusts amplification gain of the RF amplifier circuit.

6. The wireless receiver according to claim 1 , further comprising a demodulation circuit receiving the RF signal and providing the carrier strength level, and the demodulated signal supplying to a noise detection circuit, the noise muting circuit being operated according to the carrier strength level and/or noise level from the noise detection circuit.

7. A wireless receiver comprising:
an RF muting circuit that opens and closes a signal line of a demodulated signal according to a carrier strength level of a received RF signal;
a noise muting circuit that opens and closes the signal line of a demodulated signal according to a noise level in the demodulated signal;
an RF signal attenuation circuit that attenuates a level of the RF signal that is handled in an RF amplifier circuit; and
a reception mode switching unit capable of simultaneously selecting at least any two values from those comprising one of a plurality of predetermined operating levels in the RF muting circuit, one of a plurality of predetermined operating levels in the noise muting circuit, and one of a plurality of predetermined amounts of attenuation in the RF signal attenuation circuit,
wherein the RF muting circuit in the wireless receiver includes a first comparison circuit which compares an RSSI signal corresponding to an electric field strength of the received RF signal with a first set value or a second set value both of which are different to each other; and a first selection switch which switches supply of the first set value or the second set value to the first comparison circuit; the noise muting circuit includes a second comparison circuit which compares noise level in the demodulated signal with a third set value or a fourth set value both of which are different to each other; and a second selection switch which switches supply of the third set value or the fourth set value to the second comparison circuit.

8. The wireless receiver according to claim 7 , wherein the first set value is set to be greater than the second set value and the third set value is set to be greater than the fourth set value; at the time of normal operation, the reception mode switching unit switches such that the first comparison circuit selects the first set value and the second comparison circuit selects the fourth set value; and at the time of multi-wave operation, the reception mode switching unit switches such that the first comparison circuit selects the second set value and the second comparison circuit selects the third set value.

Assignees

• Audio Technica Kk

Inventors

• Shiotani Masaki

Classifications

• H03G3/3042

  in modulators, frequency-changers, transmitters or power amplifiers · CPC title

• H03G3/344

  Muting responsive to the amount of noise (noise squelch) (H03G3/345 takes precedence) · CPC title

• H03F3/19

  with semiconductor devices only · CPC title

• H04B17/336

  Signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR] · CPC title

• H04B1/10 Primary

  Means associated with receiver for limiting or suppressing noise or interference · CPC title