Radio receiver, radio transmitter, and hearing aid

• US 8,724,835 B2
• Filed: 12/15/2006
• Issued: 05/13/2014
• Est. Priority Date: 12/19/2005
• Status: Active Grant

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: NXP B.V. (NXP Semiconductors NV)
• Inventors: Kerselaers, Anthony, Elsen, Felix
• Primary Examiner(s): Page, Dale E
• Application Number:
  US12/158,314
• Publication Number:
  US 20080267436A1
• Time in Patent Office: 2,706 Days
• Field of Search: 381/68, 381/315
• US Class Current: 381/315
• CPC Class Codes: H01Q 21/29 Combinations of different interacting antenna units for giving a desired directional characteristic H01Q25/00 takes precedence
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H01Q 9/20 Two collinear substantially straight active elements; Substantially straight single active elements H01Q9/28 takes precedence
• CPC Class Codes: H01Q 9/30 with feed to end of elongated active element, e.g. unipole H01Q9/44 takes precedence

Abstract

A receiver (30) with an antenna circuit is disclosed, which antenna circuit comprises a coil (31) and either a monopole (35) or a dipole connected to the coil (31). The antenna circuit captures a signal with a wavelength transmitted by a transmitter (1). The coil (31) captures the signal and generates therefrom a current having a frequency corresponding to the wavelength. The coil (31) is dimensioned such that the current is distributed uniformly within the coil (31) at each point in time. Preferably, the monopole (35) or a leg of the dipole has a length corresponding to less than 5% of the wavelength. The invention further relates to a radio transmitter of the same kind. Finally, the invention relates to an RFID tag, a smart card, a mobile device, and a hearing aid, each comprising an inventive receiver (30) and/or an inventive transmitter.

Claims

1. A receiver with an antenna circuit, configured to capture a near field signal with a wavelength transmitted by a transmitter wherein the near field signal includes a reactive magnetic field and a reactive electric field said antenna circuit comprising:

a coil that captures said reactive magnetic field and generates therefrom a current having a frequency corresponding to said wavelength, wherein the largest dimension of said coil is less than 5% of said wavelength and said coil being dimensioned such that said current is distributed uniformly across said coil at each point in time; and

either a monopole antenna or a dipole antenna connected to said coil and that captures said reactive electric field, wherein the length of either said monopole or a leg of said dipole, as applicable, corresponds to less than 5% of said wavelength;

wherein the receiver is configured to receive a frequency of up to 30 MHz.

3. The receiver of claim 1, wherein the receiver is a component of a RFID tag.

4. The receiver of claim 1, wherein the receiver is a component of a smart card.

5. The receiver of claim 1, wherein the receiver is a component of a mobile device.

10. The receiver of claim 1, comprising a capacitor coupled to the coil, wherein the capacitance of the capacitor is selected to tune the antenna circuit to the wavelength.

2. A near field transmitter with an antenna circuit, configured to transmit a near field signal with a wavelength transmitted by the transmitter wherein the near field signal includes a reactive magnetic field and a reactive electric field said antenna circuit comprising:

a coil that transmits said reactive magnetic field wherein the coil is dimensioned such that a current flowing through said coil generates therefrom a current having a frequency corresponding to said wavelength, wherein the largest dimension of said coil is less than 5% of said wavelength and related to said transmitted reactive magnetic field is distributed uniformly across said coil at each point in time; and

either a monopole antenna or a dipole antenna connected to said coil and that transmits said transmitted reactive electric field, wherein the length of either said monopole or a leg of said dipole, as applicable, corresponds to less than 5% of said wavelength;

wherein the transmitter is configured to transmit a frequency of up to 30 MHz.

7. The transmitter of claim 2, wherein the transmitter is a component of a RFID tag.

8. The transmitter of claim 2, wherein the transmitter is a component of a smart card.

9. The transmitter of claim 2, wherein the transmitter is a component of a mobile device.

11. The receiver of claim 2, comprising a capacitor coupled to the coil, wherein the capacitance of the capacitor is selected to tune the antenna circuit to the wavelength.

6. A hearing aid system, comprising:

a first module with a sender configured to send a near field signal having a wavelength wherein the near field signal includes a reactive magnetic field and a reactive electric field; and

a second module with a loudspeaker, a receiver configured to receive said near field signal, and a signal-processing device configured to process said received near field signal and to control said loudspeaker,

wherein the receiver includes a coil that captures said reactive magnetic field and generates therefrom a current having a frequency corresponding to said wavelength, wherein the largest dimension of said coil is less than 5% of said wavelength and said coil being dimensioned such that said current is distributed uniformly across said coil at each point in time; and

either a monopole antenna or a dipole antenna connected to said coil and that captures said reactive electric field, wherein the length of either said monopole or a leg of said dipole, as applicable, corresponds to less than 5% of said wavelength;

wherein the receiver is configured to receive a frequency of up to 30 MHz.