Mobile wireless communications device with reduced microphone noise from radio frequency communications circuitry

1. A mobile wireless communications device comprising:

a housing;

a plurality of circuit boards carried by said housing and including radio frequency (RF) circuitry and a power amplifier operative each other and each carried by at least one of the circuit boards;

a microphone mounted on one of the circuit boards and operatively connected to said RF circuitry;

an antenna carried within the housing and operative with said RF circuitry;

an RF shield surrounding and isolating said microphone from the RF circuitry, power amplifier, and antenna, and shielding said microphone from radiated energy generated from the RF circuitry, antenna or power amplifier, said RF shield having a sound opening over said microphone; and

a cover extending over said RF shield and having a sound opening aligned with the sound opening in the RF shield and an acoustical tube extending from the sound opening in the cover through the sound opening in the RF shield to the microphone.

2. The mobile wireless communications device according to claim 1 , wherein at least one of said plurality of circuit boards comprises an antenna circuit board.

3. The mobile wireless communications device according to claim 1 , wherein said antenna, RF circuitry and power amplifier are supported by the same circuit board.

4. The mobile wireless communications device according to claim 1 , and further comprising an antenna circuit board wherein said antenna is mounted on said antenna circuit board.

5. The mobile wireless communications device according to claim 1 , wherein said RF shield comprises a metallic housing secured to at least one of the circuit boards and surrounding said microphone.

6. The mobile wireless communications device according to claim 1 , wherein said RF circuitry comprises a transceiver chip set.

7. The mobile wireless communications device according to claim 1 , wherein said RF circuitry is operative for generating Global Systems for Mobile (GSM) packet bursts.

8. The mobile wireless communications device according to claim 1 , and further comprising a first isolation compartment in which RF circuitry is positioned and a second isolation compartment in which said power amplifier is positioned.

9. The mobile wireless communications device according to claim 8 , wherein said RF shield surrounding said microphone is positioned adjacent said isolation compartments.

10. The mobile wireless communications device according to claim 1 , wherein said microphone comprises a surface mounted microphone and associated filter component within the RF shield.

11. The mobile wireless communications device according to claim 1 , wherein the sound opening in said cover engaging said acoustical tube is about 2.0 mm or less and configured for obtaining a desired frequency response.

12. A method for making a mobile wireless communications device, which comprises:

providing a housing, a plurality of circuit boards carried by the housing and including radio frequency (RF) circuitry and a power amplifier each carried by at least one of the circuit boards, a microphone mounted on at least one of the circuit boards and operatively connected to said RF circuitry, and an antenna positioned within the housing and operatively connected to the RF circuitry; and

isolating the microphone from the RF circuitry, power amplifier and antenna for shielding the microphone from radiated energy generated from the RF circuitry, antenna or power amplifier by securing a metallic housing to the circuit board that covers the microphone for shielding the microphone from the radiated energy, and including a sound opening in the RF shield, and positioning a cover over the RF shield and having a sound opening aligned with the sound opening in the RF shield and an acoustical tube extending from the sound opening in the cover through the sound opening in the RF shield to the microphone.

13. The method according to claim 12 , which further comprises positioning the antenna on an antenna circuit board.

14. The method according to claim 12 , which further comprises positioning the antenna, RF circuitry and power amplifier on the same circuit board.

15. The method according to claim 12 , which further comprises positioning the antenna on an antenna circuit board.

16. The method according to claim 12 , which further comprises forming a first isolation compartment on at least one of the circuit boards in which RF circuitry is positioned and a second isolation compartment in which the power amplifier is positioned.

17. A method according to claim 16 , which further comprises positioning the microphone adjacent the isolation compartments.

18. A method according to claim 12 , which further comprises surface mounting the microphone on at least one of the circuit boards.