US 7,126,545 B2 · Antenna unit and portable radio system comprising antenna unit

Abstract

A subject of the present invention is to provide an antenna unit and a portable radio device capable of attaining a wider bandwidth and a lower SAR. In the present invention, an antenna element (12) that has an effective length corresponding to a half wavelength of a transmitting frequency and a parasitic element (13) that has an effective length corresponding to a half wavelength of a receiving frequency are provided, an antenna current is induced in the antenna element (12) at the transmitting frequency upon transmitting a radio wave in a predetermined transmitting frequency band, and another antenna current is induced in the parasitic element (13) by a spatial coupling between the antenna element (12) and the parasitic element (13) at the receiving frequency upon receiving the radio wave in a predetermined receiving frequency band, whereby peak points in an antenna current distribution are scattered into two points. Accordingly, a wider bandwidth can be obtained without addition of a matching circuit and also expansion of a parts packaging space on a board and reduction in the number of packaged parts can be achieved.

Claims10

Dependent claims

A portable radio device including an antenna unit, the antenna unit comprising:

an antenna element and
a parasitic element,
wherein the antenna element has an effective length corresponding to a half wavelength or one wavelength of a transmitting frequency, to induce an antenna current that radiates a radio wave in the transmitting frequency,
the parasitic element has an effective length corresponding to a half wavelength of a receiving frequency, to induce another antenna current by a spatial coupling with the antenna element upon receiving the radio wave in the receiving frequency,
the transmitting frequency is lower than the receiving frequency, and
the parasitic element is arranged at an upper end side in the longitudinal direction of the portable radio device.

3 more elements

A portable radio device including an antenna unit, that executes transmission/reception between a first communication system and a second communication system, using radio waves in a plurality of different wavelength bands in said first and second communications systems, a frequency band in the first communication system is lower than a frequency band in the second communication system, and a maximum transmitting power of the first communication system is higher than that of the second communication system, said antenna unit comprising:

an antenna element and
a parasitic element,
wherein the antenna element has an effective length corresponding to a half wavelength or one wavelength of a frequency in the first communication system, to induce an antenna current upon using the first communication system, and
the parasitic element has an effective length corresponding to a half wavelength of a frequency in the second communication system, to induce another antenna current in the parasitic element by a spatial coupling with the antenna element upon using the second communication system,
the parasitic element is arranged at an upper end side in the longitudinal direction of the portable radio device.

2 more elements

Dependencies are inferred from the claim text.

Antenna unit and portable radio system comprising antenna unit

Life of this patent

Antenna unit and portable radio system comprising antenna unit

Life of this patent

Abstract

Claims10