US 6,633,261 B2Granted

Antenna and wireless device incorporating the same

AssigneeMatsushita Electric Industrial Co., Ltd.

InventorsHiroshi Iwai, Atsushi Yamamoto, Koichi Ogawa, Shinji Kamaeguchi, Tsukasa Takahashi, Kenichi Yamada

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Abstract

An antenna is provided which can reconcile a low antenna resonance frequency and broadband frequency characteristics, while attaining stable impedance characteristics and enhanced design flexibility. A conductive plate is coupled to a conductive base plate via a first metal lead. A voltage is applied to the conductive plate from a supply point via a second metal lead. A conductive wall is electrically coupled to the conductive plate at one end thereof. An electromagnetic field coupling adjustment plate is electrically coupled to the other end of the conductive wall. The electromagnetic field coupling adjustment plate is disposed so as to leave a predetermined interspace between itself and the conductive base plate, thereby creating a capacitor in conjunction with the conductive base plate. The conductive wall and the electromagnetic field coupling adjustment plate are disposed so as to maximize a path length from a shot-circuiting portion (at which the conductive plate is coupled to the first metal lead) to an open end of the electromagnetic field coupling adjustment plate. Preferably, a current path extending from a supply portion (at which the conductive plate is coupled to the second metal lead) to the short-circuiting portion has a length equal to a ½ wavelength for a desired resonance frequency.

Claims26

Dependent claims

An antenna for use in a wireless device, said antenna comprising:

a conductive base plate for providing a ground level;
an antenna sub-element disposed on said conductive base plate;
a supply connection member for applying a predetermined voltage to said antenna sub-element;
at least one short-circuiting connection member for short-circuiting said antenna sub-element to said conductive base plate;
and
an electromagnetic field coupling adjustment element having an end electrically coupled to said antenna sub-element,
wherein said electromagnetic field coupling adjustment element has a predetermined interspace with respect to at least one of said conductive base plate and said at least one short-circuiting connection member and extends in a direction generally parallel to said at least one of said conductive base plate and said at least one short-circuiting connection member, so as to produce an electromagnetic field coupling effect in conjunction with said at least one of said conductive base plate and said at least one short-circuiting connection member, without increasing a maximum value of a current path length, and
wherein a length from a junction of said supply connection member and said antenna sub-element to an open end of said antenna sub-element along said antenna sub-element is greater than or equal to a length from the junction-to an open end of said electromagnetic field coupling adjustment element along a portion of said antenna sub-element between said supply connection member and said electromagnetic field coupling adjustment element and said electromagnetic field coupling adjustment element.

5 more elements

An antenna for use in a wireless device, said antenna comprising:

a conductive base plate for providing a ground level;
an antenna sub-element disposed on said conductive base plate;
a supply connection member for applying a predetermined voltage to said antenna sub-element;
at least one short-circuiting connection member for short-circuiting said antenna sub-element to said conductive base plate;
and
an electromagnetic field coupling adjustment element having an end electrically coupled to said antenna sub-element,
wherein a portion of said electromagnetic field coupling adjustment element has a predetermined planar region having a predetermined interspace with respect to said conductive base plate, said predetermined planar region extending from an open end of said electromagnetic field coupling adjustment element opposite to said end electrically coupled to said antenna sub-element in a direction generally parallel to said conductive base plate toward an interspace between said antenna sub-element and said conductive base plate, so as to increase a maximum value of a current path length and produce an electromagnetic field coupling effect in conjunction with said conductive base plate, and
wherein another portion of said electromagnetic field coupling adjustment element has a predetermined interspace with respect to at least one of said conductive base plate and said at least one short-circuiting connection member and extends in a direction generally parallel to said at least one of said conductive base plate and said at least one short-circuiting connection member, so as to produce an electromagnetic field coupling effect in conjunction with said at least one of said conductive base plate and said at least one short-circuiting connection member, without increasing the maximum value of the current path length, and
wherein a length from a junction of said supply connection member and said antenna sub-element to an open end of said antenna sub-element along said antenna sub-element is greater than or equal to a length from the junction to an open end of said electromagnetic field coupling adjustment element along a portion of said antenna sub-element between said supply connection member and said electromagnetic field coupling adjustment element and said electromagnetic field coupling adjustment element.

6 more elements

Dependencies are inferred from the claim text.