Mobile wireless communications device having improved RF immunity of audio transducers to electromagnetic interference (EMI)
A mobile wireless communications device includes a housing and circuit board carried by the housing and having radio frequency (RF) circuitry and a processor operative with each other. Audio circuitry is carried by the circuit board and an audio transducer assembly, such as a speaker, has electrical contacts that electrically engage the audio circuitry for carrying audio signals between the audio circuitry and audio transducer assembly. A filter is mounted at the audio transducer assembly and reduces radio frequency (RF) electromagnetic interference to the audio transducer assembly during device operation.
1. A mobile wireless communications device comprising:
a housing;
at least one circuit board carried by the housing;
radio frequency (RF) circuitry and a processor operative therewith and carried by said at least circuit board;
an audio transducer assembly carried by said at least one circuit board and comprising an audio transducer, a transducer housing for said audio transducer, and at least one electrical contact pad member on said transducer housing and coupled to said audio transducer;
audio circuitry comprising at least one signal trace on said at least one circuit board and engaging said electrical contact pad member;
at least one first filter coupled with said at least one signal trace; and
at least one second filter mounted at said electrical contact pad member.
2. The mobile wireless communications device according to claim 1 , wherein said electrical contact pad member comprises a plurality of resilient contact pads.
3. The mobile wireless communications device according to claim 1 , wherein said at least one second filter comprises a plurality thereof connected adjacent respective resilient contact pads.
4. The mobile wireless communications device according to claim 2 , wherein said at least one second filter comprises at least one ferrite bead.
5. The mobile wireless communications device according to claim 1 , wherein said at least one second filter comprises at least one surface mount filter.
6. The mobile wireless communications device according to claim 1 , wherein said audio transducer assembly comprises a speaker within said transducer housing.
7. The mobile wireless communications device according to claim 1 , wherein one of said plurality of circuit boards comprises an antenna circuit board.
8. A mobile wireless communications device comprising:
a housing;
at least one circuit board carried by the housing;
radio frequency (RF) circuitry and a processor operative therewith and carried by said at least circuit board;
an audio transducer assembly carried by said at least one circuit board and comprising an audio transducer, a transducer housing for said audio transducer, and at least one electrical contact pad member on said transducer housing and coupled to said audio transducer;
audio circuitry comprising at least one signal trace on said at least one circuit board and engaging said electrical contact pad member;
at least one first filter coupled with said at least one signal trace; and
at least one second filter mounted within said transducer housing.
9. The mobile wireless communications device according to claim 8 , wherein said electrical contact pad member comprises a plurality of resilient contact pads.
10. The mobile wireless communications device according to claim 8 , wherein said at least one second filter comprises at least one ferrite bead.
11. The mobile wireless communications device according to claim 8 , wherein said at least one second filter comprises at least one surface mount filter.
12. The mobile wireless communications device according to claim 8 , wherein said audio transducer assembly comprises a speaker within said transducer housing.
13. The mobile wireless communications device according to claim 8 , wherein one of said plurality of circuit boards comprises an antenna circuit board.
14. A method for making a mobile wireless communications device comprising:
providing at least one circuit board within a housing, and with radio frequency (RF) circuitry and a processor operative therewith and carried by the at least circuit board;
mounting an audio transducer assembly to the at least one circuit board and comprising an audio transducer, a transducer housing for the audio transducer, and at least one electrical contact pad member on the transducer housing and coupled to the audio transducer;
providing audio circuitry comprising at least one signal trace on the at least one circuit board and engaging the electrical contact pad member;
coupling at least one first filter with the at least one signal trace; and
mounting at least one second filter at the electrical contact pad member.
15. The method according to claim 14 , wherein the electrical contact pad member comprises a plurality of resilient contact pads.
16. The method according to claim 15 , wherein the at least one second filter comprises a plurality thereof connected adjacent respective resilient contact pads.
17. The method according to claim 14 , wherein the at least one second filter comprises at least one ferrite bead.
18. The method according to claim 14 , wherein the at least one second filter comprises at least one surface mount filter.
19. A method for making a mobile wireless communications device comprising:
providing at least one circuit board within a housing, and with radio frequency (RF) circuitry and a processor operative therewith and carried by the at least circuit board;
mounting an audio transducer assembly to the at least one circuit board and comprising an audio transducer, a transducer housing for the audio transducer, and at least one electrical contact pad member on the transducer housing and coupled to the audio transducer;
providing audio circuitry comprising at least one signal trace on the at least one circuit board and engaging the electrical contact pad member;
coupling at least one first filter with the at least one signal trace; and
mounting at least one second filter within the transducer housing.
20. The method according to claim 19 , wherein the electrical contact pad member comprises a plurality of resilient contact pads.
21. The method according to claim 19 , wherein the at least one second filter comprises at least one ferrite bead.
22. The method according to claim 19 , wherein the at least one second filter comprises at least one surface mount filter.