Amplifier circuit, antenna module and wireless communication apparatus

• US 9,407,312 B2
• Filed: 09/11/2013
• Issued: 08/02/2016
• Est. Priority Date: 09/13/2012
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Tsuji, Masaaki, Kawahata, Kohji, Tsukamoto, Nobunari, Itoh, Naohiro
• Primary Examiner(s): HSIEH, PING Y
• Application Number:
  US14/428,238
• Publication Number:
  US 20150229346A1
• Time in Patent Office: 1,056 Days
• US Class Current: 1/1
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06K 19/0726 the arrangement including a circuit for tuning the resonance frequency of an antenna on the record carrier
• CPC Class Codes: H03D 1/00 Demodulation of amplitude-modulated oscillations H03D5/00, H03D9/00, H03D11/00 take precedence
• CPC Class Codes: H03F 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 3/19 with semiconductor devices only
• CPC Class Codes: H03F 3/24 of transmitter output stages
• CPC Class Codes: H04B 1/3827 Portable transceivers
• CPC Class Codes: H04B 1/40 Circuits
• CPC Class Codes: H04B 15/00 Suppression or limitation of noise or interference by means associated with receiver H04B1/10
• CPC Class Codes: H04B 2001/0408 with power amplifiers
• CPC Class Codes: H04B 5/72 for local intradevice communication
• CPC Class Codes: H04B 5/77 for interrogation

Abstract

An amplifier circuit that amplifies a carrier wave that a transmitting and receiving part has received, and includes a superimposition wave generation part that generates a superimposition wave to be superimposed onto the carrier wave; an amplifying part that adds the carrier wave and the superimposition wave to obtain an amplified carrier wave and outputs the amplified carrier wave; and an amplitude detection part that detects, based on a change in an amplitude value of the carrier wave, that the carrier wave is a predetermined carrier wave that carries a predetermined communication signal. The amplifier circuit outputs the amplified carrier wave when having detected the predetermined carrier wave.

Claims

1. An amplifier circuit that amplifies a carrier wave that a transmitting and receiving part has received, the amplifier circuit comprising:

a superimposition wave generation part that generates a superimposition wave to be superimposed onto the carrier wave;

an amplifying part that adds the carrier wave and the superimposition wave to obtain an amplified carrier wave, and outputs the amplified carrier wave;

an amplitude detection part that detects, based on a change in an amplitude value of the carrier wave, that the carrier wave is a predetermined carrier wave that carries a predetermined communication signal, wherein the amplifier circuit outputs the amplified carrier wave when the amplitude detection part has detected the predetermined carrier wave; and

a switch part that controls connection between the amplifying part and an output terminal of the amplifier circuit, wherein

the amplitude detection part controls the switch part to supply the output of the amplifying part to the output terminal of the amplifier circuit when the amplitude detection part has detected the predetermined carrier wave.

2. The amplifier circuit as claimed in claim 1, wherein

the superimposition wave generation part generates the superimposition wave that is in phase with the carrier wave and has a predetermined frequency.

3. The amplifier circuit as claimed in claim 2, further comprising

a switch part that controls connection between the amplifying part and an output terminal of the amplifier circuit, wherein

the amplitude detection part controls the switch part to supply the output of the amplifying part to the output terminal of the amplifier circuit when having detected the predetermined carrier wave.

4. The amplifier circuit as claimed in claim 3, further comprising

a switch control part that controls the switch part so as to provide an off period of time for not supplying the output of the amplifying part to the output terminal of the amplifier circuit, wherein

the superimposition wave generation part generates the superimposition wave that is in phase with the carrier that has been received during the off period of time of the switch part.

5. The amplifier circuit as claimed in claim 3, further comprising

a changeover part that switches between connection of a wireless communication part that transmits a response signal using the transmitting and receiving part via the amplifier circuit with the amplifying part and connection of a harmonic removal part that removes a harmonic component from the superimposition wave with the amplifying part, wherein

the changeover part

supplies an output of the harmonic removal part to the amplifying part when the amplitude detection part has detected the predetermined carrier wave, and

supplies an output of the wireless communication part to the amplifying part when having detected the output of the wireless communication part.

6. The amplifier circuit as claimed in claim 1, further comprising

a switch control part that controls the switch part so as to provide an off period of time for not supplying the output of the amplifying part to the output terminal of the amplifier circuit, wherein

the superimposition wave generation part generates the superimposition wave that is in phase with the carrier that has been received during the off period of time of the switch part.

7. An antenna module comprising:

a transmitting and receiving part that wirelessly transmits and receives signals; and

the amplifier circuit according to claim 1, to amplify a carrier wave that the transmitting and receiving part has received.

8. A wireless communication apparatus comprising:

a transmitting and receiving part that wirelessly transmits and receives signals;

the amplifier circuit according to claim 1, to amplify a carrier wave that the transmitting and receiving part has received; and

a wireless communication part that carries out communication using the signals.

10. An antenna module comprising:

a transmitting and receiving part that wirelessly transmits and receives signals; and

the amplifier circuit according to claim 5, to amplify a carrier wave that the transmitting and receiving part has received.

9. An amplifier circuit that amplifies a carrier wave that a transmitting and receiving part has received, the amplifier circuit comprising:

a superimposition wave generation part that generates a superimposition wave to be superimposed onto the carrier wave;

an amplifying part that adds the carrier wave and the superimposition wave to obtain an amplified carrier wave, and outputs the amplified carrier wave;

an amplitude detection part that detects, based on a change in an amplitude value of the carrier wave, that the carrier wave is a predetermined carrier wave that carries a predetermined communication signal, wherein the amplifier circuit outputs the amplified carrier wave when the amplitude detection part has detected the predetermined carrier wave; and

a changeover part that switches between connection of a wireless communication part that transmits a response signal using the transmitting and receiving part via the amplifier circuit with the amplifying part and connection of a harmonic removal part that removes a harmonic component from the superimposition wave with the amplifying part, wherein

the changeover part

supplies an output of the harmonic removal part to the amplifying part when the amplitude detection part has detected the predetermined carrier wave, and

supplies an output of the wireless communication part to the amplifying part when having detected the output of the wireless communication part.

11. A wireless communication apparatus comprising:

a transmitting and receiving part that wirelessly transmits and receives signals;

the amplifier circuit according to claim 9, to amplify a carrier wave that the transmitting and receiving part has received; and

a wireless communication part that carries out communication using the signals.