Capacitor assembly and communications device including the capacitor assembly
View Patent ↗A communications device ( 125 ) and capacitor assembly ( 100 ) having a first capacitor electrode formed by a conductive keypad mount ( 110 ) coupled to a conductive part of a housing ( 120 ) of the communications device ( 125 ). The keypad mount ( 110 ) has keypad apertures ( 210 ) aligned with keys ( 140 ) of a keypad ( 145 ) and the conductive part of the housing ( 120 ) has an external housing covering insulator in the form of the window sub-housing ( 121 ). There is a circuit board ( 130 ) providing support for a second capacitor electrode ( 150 ). The circuit board ( 130 ) has an array of keypad actuators ( 135 ) aligned with the keys ( 140 ).
1. A communications device including a capacitor assembly comprising:
a housing;
a first capacitor electrode formed by a conductive keypad mount coupled to a conductive part of the housing of the communications device, wherein the first capacitor electrode is carried in the housing, the keypad mount having keypad apertures aligned with keys of a keypad and the conductive part of the housing having an external housing covering insulator thereon;
a circuit board carried in the housing, the circuit board including an array of keypad actuators thereon, the keypad actuators being aligned with the keys of the keypad;
a second capacitor electrode carried in the housing;
a dielectric disposed between the first capacitor electrode and the second capacitor electrode; and
an antenna radiator element mounted in the housing, wherein the first capacitor electrode, the second capacitor electrode, and the dielectric form the capacitor assembly, wherein the capacitor assembly is parasitically coupled in parallel to the antenna radiator element.
2. A communications device as claimed in claim 1 , wherein the conductive part of the housing at least partially surrounds a display screen window in the housing.
3. A communications device as claimed in claim 1 , wherein the conductive keypad mount comprises a frame mounted to the housing.
4. A communications device as claimed in claim 3 , wherein the frame has at least one contact surface coupling the conductive keypad to the conductive part of the housing.
5. A communications device as claimed in claim 1 , wherein the housing and keypad provide an external first capacitor electrode covering insulator.
6. A communications device as claimed in claim 1 , wherein the capacitor assembly, in use, reduces the effects of parasitic inductances associated with the antenna radiator element.
7. A communications device as claimed in claim 1 , wherein dielectric is formed by at least a membrane forming part of the keypad.
8. A communications device as claimed in claim 1 , wherein the second capacitor electrode is formed by at least a metal sheet.
9. A communications device as claimed in claim 8 , wherein the second capacitor electrode has apertures therein allowing operative coupling of the keys with respective aligned said keypad actuators.
10. A communications device as claimed in claim 1 , wherein the second capacitor electrode is supported by the circuit board.
11. A communications device as claimed in claim 1 , wherein the first capacitor electrode has a larger effective surface are than that of the second capacitor electrode.
12. A communications device as claimed in claim 1 , wherein the first capacitor electrode has a tapered side adjacent the antenna radiator element, wherein an end of the radiator element furthest from an associated feed point is closest to the tapered side and an end of the radiator element closest to the feed point is furthest from the tapered side.