JP2009005245A - V beam antenna - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems such as a conventional TV indoor antenna, a rod antenna for VHF and a loop antenna for UHF in most situations, has few gains and cannot receive at other areas than a strong electric field area, and a Yagi antenna (R) for outdoors in most situations needs more wave directors for increasing the gains, causing a boom to be longer and larger. <P>SOLUTION: The entire length of a first conductor and a second conductor is made 3/2λ to create a V shape, and a parasitic element being 1/2λ of the entire length of the V shape is inserted inside with an apex conductor as a feeding point. Thus, alignment of broadband and impedance is improved. Further, 1/4λ at the tip of the element is horizontalized to create a modified V beam antenna. Thus, the gain is improved. When the antenna is designed according to the UHF of the television, the antenna is operated as 1/2λ in the VHF (4ch to 12ch). Thus, the antenna can be used with only one antenna. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a V-beam antenna having a wide band characteristic.

Figure 5 shows a typical TV indoor antenna. A rod antenna is often used for VHF, and a loop antenna is used for UHF. However, the indoor antenna could not be used unless the gain was low and the area was a strong electric field. Although there is a V dipole in Patent Document 1, the overall length is 1 / 2λ, and the gain cannot be expected to improve much. Patent Document 2 is V-shaped, but this changes the beam pattern by changing the angle up to 1.2λ, which causes a problem in impedance matching. General V-beam antennas are not practically used because they become several wavelengths and become large. A 3 / 2λ curved antenna has also been devised. There is a problem in reproducibility and it has not been put to practical use.
JP 2006-203714 A JP 09-260927 A

In order to eliminate the above-described conventional technique, the present invention requires a wider band and higher gain.
There was a problem that a single antenna could be used with a V / UHF TV antenna.

The V-beam antenna according to the first invention has a total length of 3 / 2λ and is V-shaped to provide directivity and increase gain. The V-shaped angle is 120 degrees, and a V-shaped parasitic element having a total length of ½λ is arranged on the inner side to achieve broadband and impedance matching. FIG.

The V-beam antenna according to the second invention is a modified V-beam antenna in which a 1 / 4λ portion is horizontal from the tip of each element of the first antenna. The angle is 90 degrees compared to the antenna of the first aspect. The gain will increase by 1 db. FIG.

The V-beam antenna according to the third aspect of the invention is designed to have a wide band in order to support terrestrial digital television. FIG. 3 shows an antenna in which the tips of several conductors having different lengths are connected. Reference numerals 3 and 4 are feeding points.

This V-beam antenna has a long element length, but the gain is increased and the bandwidth is widened. If the VHF / UHF antenna is three times the frequency by design, one antenna is sufficient.

It is an antenna that can cover the frequency of televisions in the UHF / VHF band with one element. The V-beam antenna shown in FIG. 6 has a total length of 3 / 2λ as a multi-line shape. The UHF beam pattern is shown in FIG. 8, and the VSWR frequency characteristics are shown in FIGS. If designed in this way, many indoor antennas are currently used, but the VHF (high band) and UHF antennas are directional and slightly longer, but only one antenna is needed. It is available as economical. Gain is higher than conventional antennas. (Gain: 5db)

As an application example, FIG. 10 is a perspective view of a three-element modified V-beam antenna that can be used in 435 MHz and 145 MHz and each element has a second shape. The parasitic element is removed, and the gain is 9.5 db at 435 MHz and 5 db at 145 MHz. FIG. 13 shows a V-beam antenna that can be used for both frequencies, but the gain is lower by about 0.5 db than the modified V-beam antenna. The beam pattern 435MHZ of the modified V beam antenna is shown in FIG. 11 as 145MHZ in FIG.

It can be used as an indoor antenna for digital terrestrial broadcasting.

It is a top view of the V beam antenna in a 1st embodiment concerning the present invention. It is a top view of the modified V beam antenna in 2nd Embodiment concerning this invention. It is a top view of the V beam antenna in the 3rd embodiment concerning the present invention. It is a top view of the deformation | transformation V beam antenna in 4th Embodiment concerning this invention. It is a schematic diagram of a loop antenna in a conventional antenna TV antenna, a VHF antenna, a rod antenna, and a UHF antenna. It is a perspective view of the multi-line type | formula deformation | transformation V beam antenna 1 element antenna for televisions in 4th Embodiment. (With parasitic elements) FIG. 7 is a TV UHF band VSWR characteristic diagram of the multi-line deformed V-beam antenna of FIG. 6. (470 MHz to 710 MHz) FIG. 7 is a TV UHF directivity pattern characteristic diagram of the multi-line deformed V-beam antenna of FIG. 6. (530MHZ) FIG. 7 is a frequency characteristic diagram of a television VHF band VSWR of the multi-line deformed V-beam antenna of FIG. 6. (175MHZ ~ 210MHZ) FIG. 4 is a perspective view of a three-element modified V-beam antenna that can be used at 435 MHz and 145 MHz as a reference example. FIG. 11 is a beam pattern diagram of the 3-element modified V-beam antenna of FIG. 10. (435MHZ, Gain: 9.5db) FIG. 11 is a directivity pattern characteristic diagram of the three-element modified V-beam antenna of FIG. 10. (145MHZ) It is a perspective view of a 3 ele V beam antenna (145 MHZ, 435 MHZ).

Explanation of symbols

1 and 2: Antenna conductors 3 and 4: Feed points 5 and 6: Parasitic element 7: Radiator 8: Reflector 9: Wave director

Claims (4)

The total length of the first conductor and the second conductor is 3 / 2λ, where the design frequency is one wavelength (λ).
The conductor is a linear antenna that is V-shaped from the center of the entire length and feeds the apex (one side 3 / 4λ) of the V-shaped parasitic element with a total length of 1 / 2λ inside it. V-beam antenna characterized by using a conductor 2. A modified V beam antenna according to claim 1, wherein a quarter λ portion at the tip of each element is made horizontal. A linear antenna of the V-beam antenna according to claim 1, wherein several conductors of different lengths are combined. 3. A modified V beam antenna comprising: a linear antenna of the V beam antenna according to claim 2 combined with several conductors having different lengths.

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