APPARATUS COMPRISING A BROADCAST RECEIVER CIRCUIT AND PROVIDED WITH AN ANTENNA

• US 20110028114A1
• Filed: 03/19/2009
• Published: 02/03/2011
• Est. Priority Date: 03/21/2008
• Status: Active Grant

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: NXP B.V. (NXP Semiconductors NV)
• Inventors: Kerselaers, Anthony
• Granted Patent: US 9,054,773 B2
• Time in Patent Office: Days
• US Class Current: 455/296
• CPC Class Codes: H04B 1/18 Input circuits, e.g. for coupling to an antenna or a transmission line coupling networks between antennas or lines and receivers independent of the nature of the receiver H03H

Abstract

The invention relates to an apparatus 1 comprising a broadcast receiver circuit, an embedded antenna for receiving broadcast signals and a tuning circuit coupled between the antenna and the receiver circuit, which tuning circuit comprises a filter circuit coupled to ground, wherein the tuning circuit is designed to have a first resonance at a first frequency below a broadcast band of interest, and a second resonance at a second frequency above the broadcast band and wherein the tuning circuit comprises an amplifier with an output to the receiver circuit and with an input to the filter circuit, and wherein the tuning circuit is provided with a carrier to noise ratio (CNR) which is substantially fiat across the broadcast band.

Claims

1. An apparatus comprising a broadcast receiver circuit, an embedded antenna for receiving broadcast signals and a tuning circuit coupled between the antenna and the receiver circuit, which tuning circuit comprises a filter circuit coupled to ground, wherein the tuning circuit is designed to have a first resonance at a first frequency below a broadcast band of interest, and a second resonance at a second frequency above the broadcast band and wherein the tuning circuit comprises an amplifier with an output to the receiver circuit and with an input to the filter circuit, and wherein the tuning circuit is provided with a carrier to noise ratio (CNR) which is substantially flat across the broadcast band.

2. A system as claimed in claim 1, wherein the filter circuit and the amplifier have a comparable noise level.

3. An apparatus as claimed in claim 1, wherein the embedded antenna is small compared with wavelengths corresponding to the broadcast band.

4. An apparatus as claimed in claim 1, wherein the amplifier has an input impedance in the range of 20Ω

to 500Ω

for an inductive antenna, and 300Ω

to 2 Ω

for a capacitive antenna.

5. An apparatus as claimed in claim 4, wherein the amplifier comprises a internal feedback to the input.

6. A system as claimed in claim 4, wherein the noise level of the amplifier is reduced in that the amplifier has an input electrode with a reduced resistance connection.

7. A system as claimed in claim 6, wherein the input electrode is connected to the base of a bipolar transistor with an increased surface area.

8. A system as claimed in claim 1, wherein the filter circuit comprises inductors, which inductors have quality factors in the range of 30 to 100.

9. A system as claimed in claim 1, further comprising a transmit circuit coupled to the filter circuit for wireless transmission of audio signals through the antenna, wherein the filter circuit is designed to operate as a filter for suppressing of harmonics in a transmitted signal.

10. A system as claimed in claim 1, wherein the antenna is a capacitive antenna.

11. A system as claimed in claim 9, wherein the transmit circuit has an output impedance that is substantially equal to the input impedance of the amplifier.

12. A method of receiving a signal in a system as claimed in claim 1, comprising the steps of:

switching the system to a receive mode such that broadcasted signals cannot enter the transmit circuit

receiving the signals through the tuning circuit and the antenna.

13. A method of transmitting signals in a system as claimed in claim 9, comprising the steps of:

switching the system to a transmit mode such that transmitted signals cannot enter the amplifier and the broadcast receiver circuit;

transmitting the signals through the tuning circuit and the antenna to generate an effective radiated power of 1 uW or less.

14. An integrated circuit for use in the system as claimed in claim 1 comprising the amplifier and the broadcast receiver circuit, and the transmit circuit if available.