Coplanar antenna
A coplanar antenna including a conductive plane, wherein the length of the conductive plane along a first dimension is less than one-quarter of a wavelength of a resonant frequency; an insulating region within the conductive plane, wherein the insulating region is of a shape that outlines a conductive peninsula, wherein: the conductive peninsula is coupled to the conductive plane, the conductive peninsula is substantially coplanar to a major portion of the conductive plane, the conductive peninsula is operable to be electrically coupled to an electric feed circuit, and the conductive peninsula is operable to electrically couple a tunable inductance to the conductive plane after receiving a current from the electric feed circuit.
1. A personal sensor bracelet comprising:
a curved conductive band comprising:
a substantially planar portion having a first end and a second end;
a first curved portion extending from the first end of the substantially planar portion;
a second curved portion extending from the second end of the substantially planar portion;
a coplanar antenna disposed, the coplanar antenna comprising:
a single conductive plane having a first dimension and a second dimension, wherein the length of the single conductive plane along the first dimension is the radiating element length of the coplanar antenna and is less than or equal to one-quarter of a wavelength of a resonant frequency, wherein a major portion of the single conductive plane is disposed within the substantially planar portion;
an insulating region disposed within the single conductive plane, wherein the insulating region is of a shape that outlines a conductive peninsula, wherein:
the conductive peninsula is coupled to the single conductive plane;
the conductive peninsula is substantially coplanar to the major portion of the single conductive plane;
the conductive peninsula electrically couples a tunable inductance to the single conductive plane;
the conductive peninsula is not substantially electrically resonant at the resonant frequency; and
the conductive peninsula is electrically coupled to an electric feed circuit;
wherein the curved conductive band, including the single conductive plane and the conductive peninsula, is formed from an integral piece of conductive material;
a first electrical connection that electrically couples the conductive plane to the electric feed circuit;
a second electrical connection that electrically couples the conductive peninsula to the electric feed circuit, wherein the first electrical connection is positioned at a point along the first dimension distal from the second electrical connection;
a processor disposed within the substantially planar portion, the processor electrically coupled to the electric feed circuit; and
a plurality of sensors disposed within the substantially planar portion, the plurality of sensors electrically coupled to the processor; and
a second curved band coupled to the curved conductive band such that the second curved band and the curved conductive band form a bracelet, wherein the second curved band is removably coupled to the curved conductive band at an end of the first curved portion distal from the substantially planar portion, and the second curved band is removably coupled to the curved conductive band at an end of the second curved portion distal from the substantially planar portion.
2. The personal sensor bracelet of claim 1 , wherein the single conductive plane is not covered by an insulating radome in operation.
3. The personal sensor bracelet of claim 1 , wherein the insulating region is substantially filled by a dielectric material.
4. The personal sensor bracelet of claim 1 , wherein the electric feed circuit comprises a tuning circuit operable to electrically compensate for a portion of the wavelength of the resonant frequency.