Mobile wireless communications device having improved antenna impedance match and antenna gain from RF energy

• US 20060223597A1
• Filed: 04/04/2005
• Published: 10/05/2006
• Est. Priority Date: 04/04/2005
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Qi, Yihong, Bandurska, Krystyna, Man, Ying Tong, Zhu, Lizhong, Corrigan, Michael
• Granted Patent: US 7,483,727 B2
• Time in Patent Office: Days
• US Class Current: 455/575.500
• CPC Class Codes: H04M 1/0202 Portable telephone sets, e.g. cordless phones, mobile phones or bar type handsets constructional features of telephone transmitters or receivers, e.g. of speakers or microphones H04M1/03
• CPC Class Codes: H04M 1/026 Details of the structure or mounting of specific components
• CPC Class Codes: H04M 1/6008 in the transmitter circuit
• CPC Class Codes: H04M 1/6016 in the receiver circuit

Abstract

A mobile wireless communications device and associated method of making same includes a housing and circuit board having a ground plane. Radio frequency (RF) circuitry and a processor are carried by the circuit board and operative with each other. An antenna is carried by the housing and operative with the RF circuitry. Audio circuitry is carried by the circuit board and operative with the RF circuitry and processor. An audio transducer assembly such as a receiver is carried by the circuit board and engages audio circuitry for carrying audio signals between the audio circuitry and speaker. A filter is mounted at the speaker for blocking RF energy from the antenna through the speaker to the ground plane and decoupling the antenna from the speaker and any other components on the circuit board to minimize any detuning of antenna impedance match and degradation in antenna gain.

Claims

1. A mobile wireless communications device comprising:

a housing;

a circuit board having a ground plane and carried by the housing;

radio frequency (RF) circuitry and a processor operative with each other and carried by the circuit board;

an antenna carried by the housing and operative with the RF circuitry;

audio circuitry carried by the circuit board and operative with the RF circuitry and processor;

an audio transducer assembly carried by the circuit board and having electrical contacts that electrically engage audio circuitry for carrying audio signals between the audio circuitry and the audio transducer assembly; and

a filter mounted at the audio transducer assembly for blocking RF energy from the antenna through the audio transducer assembly to the ground plane and decoupling the antenna from the audio transducer assembly and any other components on the circuit board to minimize any detuning of antenna impedance match and degradation in antenna gain.

2. A mobile wireless communications device according to claim 1, wherein said filter is operative for low DC resistance and high impedance from about 500 MHz to about 3 GHz.

3. A mobile wireless communications device according to claim 1, wherein said filter is serially connected within said audio circuitry.

4. A mobile wireless communications device according to claim 1, wherein said audio transducer assembly includes a transducer housing, wherein said filter is positioned within said transducer housing.

5. A mobile wireless communications device according to claim 1, wherein said electrical contacts comprise resilient contact pads that engage the audio circuitry.

6. A mobile wireless communications device according to claim 5, wherein said audio transducer comprises a transducer housing and said filter is located between said audio transducer housing and resilient contact pads.

7. A mobile wireless communications device according to claim 1, wherein said filter is located adjacent the electrical contacts of said audio transducer assembly.

8. A mobile wireless communications device according to claim 1, wherein said filter comprises a ferrite bead.

9. A mobile wireless communications device according to claim 1, wherein said filter comprises a serial inductor or shunt capacitor.

10. A mobile wireless communications device according to claim 1, wherein said filter comprises a RF shield that surrounds the audio transducer assembly.

11. A mobile wireless communications device comprising:

a housing;

a circuit board having a ground plane and carried by the housing;

radio frequency (RF) circuitry and a processor operative with each other and carried by the circuit board opposite the ground plane;

an antenna carried by the housing and operative with the RF circuitry;

audio circuitry carried by the circuit board and operative with the RF circuitry and processor and including a receiver audio switch and audio connection lines carried by the circuit board and interconnecting the RF circuitry, processor and receiver audio switch;

a speaker carried by the circuit board and having electrical contacts that electrically engage the audio connection lines for carrying audio signals between the audio circuitry and speaker; and

a filter mounted at the speaker for blocking RF energy from the antenna through the speaker to the ground plane and decoupling the antenna from the speaker and any other components on the circuit board to minimize any detuning of antenna impedance match and degradation in antenna gain.

12. A mobile wireless communications device according to claim 11, wherein said filter is operative for low DC resistance and high impedance from about 500 MHz to about 3 GHz.

13. A mobile wireless communications device according to claim 11, wherein said receiver audio switch includes a detect circuit for detecting when a respective headset is operatively connected to said audio circuitry.

14. A mobile wireless communications device according to claim 11, wherein said audio circuitry further comprises a jack carried by the housing, and jack connection lines carried by said circuit board and operatively connected to said jack, processor and receiver audio switch.

15. A mobile wireless communications device according to claim 11, wherein said filter is serially connected within an audio connection line.

16. A mobile wireless communications device according to claim 11, wherein said speaker comprises a speaker housing and said filter is positioned within said speaker housing.

17. A mobile wireless communications device according to claim 11, wherein said electrical contacts comprise resilient contact pads that engage the audio connection lines.

18. A mobile wireless communications device according to claim 17, wherein said speaker comprises a speaker housing and said filter is located between said speaker housing and resilient contact pads.

19. A mobile wireless communications device according to claim 11, wherein said filter comprises a ferrite bead.

20. A mobile wireless communications device according to claim 11, wherein said filter comprises a serial inductor or shunt capacitor.

21. A mobile wireless communications device according to claim 11, wherein said RF filter comprises a RF shield that surrounds the audio transducer assembly.

22. A method of making a mobile wireless communications device, which comprises:

providing a housing, a circuit board having a ground plane and carried by the housing, radio frequency (RF) circuitry and a processor operative with each other and carried by the circuit board, an antenna carried by the housing and operative with the RF circuitry, audio circuitry carried by the circuit board and operative with the RF circuitry and processor, and an audio transducer assembly carried by the circuit board and having electrical contacts that electrically engage audio circuitry for carrying audio signals between the audio circuitry and the audio transducer assembly; and

mounting a filter at the audio transducer assembly for blocking RF energy from the antenna through the speaker to the ground plane and decoupling the antenna from the speaker and any other components on the circuit board to minimize any detuning of antenna impedance match and degradation in antenna gain.

23. A method according to claim 22, which further comprises mounting a filter that is operative for low DC resistance and high impedance over about 500 MHz to about 3 GHz.

24. A method according to claim 22, which further comprises serially connecting the filter within audio circuitry.

25. A method according to claim 22, which further comprises positioning the filter within a housing of the audio transducer assembly.

26. A method according to claim 22, which further comprises positioning the filter adjacent the electrical contacts.

27. A method according to claim 22, which further comprises forming the filter as a ferrite bead, shunt capacitor or serial inductor.

28. A method according to claim 22, which further comprises forming a RF shield around the audio transducer assembly.