JP2001345635A - Helical antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a helical antenna that can be manufactured and assembled appropriately, has improved manufacturing economy, and can be miniaturized. SOLUTION: This helical antenna includes a plurality of conductors 13 and 15 for receiving at least a plurality of kinds of electric waves being provided at a columnar member 11 that is made of an insulator, each of the conductors 13 and 15 is provided at the columnar member 11 helically corresponding to each of regions obtained by dividing an axial direction into a plurality of regions, and a plurality of terminal parts 17 and 18 for output that are connected to each of the plurality of conductors 13 and 15 that are guided to one end side in the axial direction of the columnar member 11 from the region are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention receives digital radio broadcasts by receiving radio waves from artificial satellites (hereinafter also referred to as "satellite waves") or radio waves on the ground (hereinafter also referred to as "terrestrial waves"). Digital radio receivers, and in particular to antennas used in digital radio receivers.

[0002]

2. Description of the Related Art Recently, a digital radio receiver capable of receiving a radio wave (satellite wave) or a terrestrial wave from an artificial satellite so as to listen to a digital radio broadcast has been developed and is being put to practical use in the United States.

This digital radio receiver is mounted on a mobile station such as an automobile, and can receive radio waves having a frequency of about 2.3 GHz to listen to radio broadcasts. That is, the digital radio receiver is a radio receiver that can listen to mobile broadcasts. The terrestrial wave is obtained by temporarily receiving a satellite wave at an earth station and then slightly shifting the frequency.

[0004] In order to receive such a radio wave having a frequency of about 2.3 GHz, it is necessary to install an antenna outside the vehicle. As such an antenna, various antennas can be considered, but a stick type is generally used instead of a flat type (flat type).

As is well known, an electromagnetic wave radiated in free space is a transverse wave having an electric field and a magnetic field oscillating in a plane perpendicular to the traveling direction of the wave, and the electric field and the magnetic field have intensities in the plane. Changes, which is called polarization. Satellite waves are circularly polarized waves, whereas terrestrial waves are linearly polarized waves.

The first antenna device shown in FIG. 2 supplies a first antenna 21 for receiving a satellite wave, a case 22 in which the first antenna 21 is erected and held, and a power supply voltage. And a cable 27. The second antenna device includes a second antenna 23 for receiving terrestrial waves.
And a case 2 in which the second antenna 23 is erected and held
5 and a cable 28 for supplying a power supply voltage.

[0007] Such first and second antennas 21,
The satellite wave and the terrestrial wave received at 23 are combined by adjusting the phase by shifting the phase by a phase shifter (adjusted), and then provided in the cases 22 and 24, not shown. It is amplified by a low noise amplifier (LNA) and sent to the receiver body. Here, the combination of the first and second antennas 21 and 23, the phase shifter, and the LNA is called an antenna device. As a well-known example of an antenna device, there is Japanese Patent Application Laid-Open No. 8-204442.

[0008]

As described above, in the conventional antenna device, the first and second antennas 21 and 23 are erected on the cases 22 and 24 to receive satellite waves and terrestrial waves. Therefore, two antennas and two cases 22 and 24 are required, so that there is a problem that time is required for manufacturing and assembling work, and that the entire device is enlarged.

[0009] Therefore, an object of the present invention is to provide a helical antenna which can constitute a terrestrial wave and a satellite wave by one member, is economical, and can be reduced in size.

[0010]

According to the present invention, a columnar member (11) made of an insulator and a plurality of conductors (13) provided on the columnar member (11) for receiving at least a plurality of types of radio waves are provided. , 15), the helical antenna includes:
Each of the conductors (13, 15) is provided in the columnar member (11) in a helical shape corresponding to each of the regions divided into a plurality of axial directions, and the columnar member (11) is provided from each of the regions. 11) A helical antenna having a plurality of output terminals (17, 18) connected to the conductors (13, 15) guided to one end in the axial direction, respectively. can get.

Note that the reference numerals in parentheses are provided for facilitating the understanding of the present invention, and are merely examples, and it is a matter of course that the present invention is not limited to these.

[0012]

The radio waves received by the first and second conductors are received by conductors provided in a plurality of regions of one columnar member. The received radio waves are combined by synchronizing (adjusting) the phases by shifting the phase by a phase shifter, then amplified by a low noise amplifier (LNA), and sent to the receiver body.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. A helical antenna according to one embodiment of the present invention will be described with reference to FIG. The illustrated helical antenna includes one columnar member 11 made of an insulator, a plurality of conductors 13 provided on the columnar member 11 for receiving satellite waves, and a second conductor for receiving terrestrial waves. 15 is provided.

The columnar member 11 has first and second regions A and B in which the axial direction is divided into two. In the first region A, a first conductor 13 is provided in a helical shape (spiral shape). In the second region B, a second conductor 15 is provided in a helical shape. The first conductor 13 is guided to one end of the columnar member 11 in the axial direction, and the first output terminal 1
8 is connected. The second conductor 15 is formed of the columnar member 11.
And is connected to the second output terminal 18.

The columnar member 11 is a cylindrical or columnar member, and the first and second conductors 1 are formed on the outer peripheral surface of the columnar member 11.
3, 3 and 15 are wound in a helix. As a material of the columnar member 11, an insulating material such as plastic is used.

The first conductor 13 plays a role of efficiently receiving left circularly polarized waves for satellite waves. Second conductor 15
Functions to efficiently receive linearly polarized waves for terrestrial waves.

The first conductor 13 for a sanitary wave
Are used. Second conductor 1 for terrestrial waves
5, one is used, for example. Note that the first and second
The number of the conductors 13 and 14 is not limited to these.

The first and second conductors 13 and 15 are formed by printing a plurality of conductor patterns on an insulating sheet or by winding a conductive linear member around the columnar member 11. In the helical antenna having such a structure, the resonance frequency is determined by the height (length), diameter, permittivity, and the like of the columnar member 11.

Here, in the helical antenna according to this embodiment, the columnar member 11 has a case 25 shown in FIG.
The case 25 is connected to a cable for supplying the same power supply voltage as the cable 27 shown in FIG.

The satellite wave (circularly polarized wave) received by the first conductor 13 in the first region A of such a columnar member 11.
Are synthesized by matching (adjusting) the phases by shifting the phase by a phase shifter (not shown) provided in the case, and then combining the low noise amplifier (LN
It is amplified by A) and sent to the receiver body. Also,
Similarly, reception is performed on the second conductor 15.

Although the present invention has been described with reference to the preferred embodiment, the present invention is, of course, not limited to the above-described embodiment. For example, in the above embodiment, the first region A has a dimension longer in the axial direction than the second region B, but may have the opposite dimension. Further, the width of the conductor pattern of the first and second conductors 13 and 15 and the interval between the first and second conductors 13 and 15 can be arbitrarily adjusted.

Further, in the above-described embodiment, the first area A has two types, that is, the second area B. However, if more types of radio waves are to be received, the area is increased. Of course, it may be adopted.

[0023]

As is apparent from the above description, in the present invention, a plurality of conductors can be provided according to the type of radio wave by setting a plurality of regions on one columnar member. It is possible to provide a helical antenna which is excellent in manufacturing efficiency and can be reduced in size.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of a helical antenna according to one embodiment of the present invention.

FIG. 2 is a front view showing a configuration of a conventional antenna device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Column member 13, 15 Conductor 17, 18 Output terminal part 21 1st antenna 23 2nd antenna 22, 24 Case A 1st area B 2nd area

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5J021 AA02 AA07 AA13 AB02 HA10 JA03 JA06 JA07 5J046 AA02 AA07 AA19 AB12 BA02 TA03

Claims (3)

[Claims] In a helical antenna including a columnar member made of an insulator and a plurality of conductors provided on the columnar member for receiving at least a plurality of types of radio waves, the columnar member has an axial direction. Each of the conductors is provided in a helical shape corresponding to each of the plurality of divided regions, and is connected to each of the conductors guided from each of the regions to one end of the columnar member in the axial direction. A helical antenna having a plurality of output terminals. 2. The helical antenna according to claim 1, wherein each of said conductors is a conductor pattern wound in a helix around an outer peripheral surface of said columnar member. 3. The helical antenna according to claim 1, wherein each of the plurality of regions includes a conductor for receiving circularly polarized waves in at least one of the regions and a region different from the one of the regions. A helical antenna, wherein the conductor for receiving linearly polarized waves is arranged.