US 6,642,904 B2 · Antenna

Abstract

An antenna is provided to improve the gain and to eliminate various negative effects caused by a surrounding environment in which the antenna is mounted, such as the effects caused by neighboring metal plates and the like, while providing an antenna structure to facilitate its assembly into various communication devices. The antenna emitting radio waves at a center frequency has an antenna main body and a grounding line section connected to the ground-side of the coaxial cable for supplying power to the antenna main body. The grounding line section starts from a reference point and extends in a loop so as to surround the antenna main body, and portions of the conductor line are severed so as to provide a first end terminal and a second end terminal so that the length of the conductor line from the reference point to the first end terminal corresponds to one quarter of a wavelength of the center frequency or its integral multiple.

Claims10

Dependent claims

An antenna comprising:

an antenna main body that resonates at a center frequency and emits radio waves at the center frequency;
a grounding line section connected to a ground-side of a feed line supplying power to the antenna main body, said grounding line section having a conductor portion that extends from a start terminal at which the grounding line section is connected to the feed line to a first end terminal;
and
an impedance matching section provided between a feed end of the antenna main body and the feed line for matching impedance values, the impedance matching section having a matching inductance section such that ends of the matching inductance section are connected electrically to the feed end of the antenna main body and to a midpoint between the start terminal of the grounding line section and the first end terminal, respectively,
wherein a length of the conductor portion extending from the start terminal of the grounding line section to the first end terminal of the grounding line section is one quarter or an integral multiple of one quarter of the wavelength of a radio wave at the center frequency.

2 more elements

An antenna comprising:

an antenna main body that resonates at a center frequency and emits radio waves at the center frequency;
a grounding line section connected to a ground-side of a feed line supplying power to the antenna main body, said grounding line section having a conductor portion that extends from a start terminal at which the grounding line section is connected to the feed line to a first end terminal;
and
a frequency adjusting capacitance section provided between an exit end of the antenna main body opposite to the feed point of the antenna main body and the second end terminal of the grounding line section for adjusting the center frequency,
wherein a length of the conductor portion extending from the start terminal of the grounding line section to the first end terminal of the grounding line section is one quarter or an integral multiple of one quarter of the wavelength of a radio wave at the center frequency, and
wherein the grounding line section further has a conductor portion formed by extending from the start terminal to a second end terminal that is distanced from the first end terminal.

3 more elements

Dependencies are inferred from the claim text.

Antenna

Life of this patent

Antenna

Life of this patent

Abstract

Claims10