JP3046611U - Variable coil for broadband tuned antenna - Google Patents

Abstract

(57) [Summary] (With correction) [PROBLEMS] To improve the structure of a loading coil of a wideband antenna from an HF band to a low VHF frequency band. SOLUTION: A variable coil 4 of a loading coil which is brought into contact with a contact part 5 of a coil housing part 2 and tunes an antenna is provided.
The frequency band is divided into a plurality of frequency bands, and the densely wound part and the loosely wound part are set as one set, and the band is sequentially wound for each frequency band. The low frequency band of HF is F1, the intermediate frequency band is F2, and the VHF frequency is 50 MHz.
Assuming that the band is F3, the close winding of the frequency band F3 is performed by winding the close winding coil L3 from the rod 6 side, and then winding the loose winding coil L3A in the fine adjustment region. Next, the close-wound coil L2 for the frequency band F2 is wound, followed by the loosely wound coil L2 for the frequency band F2.
Wind 2A. Subsequently, the tightly wound coil L1 of the frequency band F1 is wound, and the loosely wound coil L1A is wound in the same manner as the densely wound coil L2 to form a variable coil. The loosely wound portion L1A is a fine adjustment range of the frequency band F1 where HF is low.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to an antenna having an antenna tuning function in a plurality of frequency bands, and particularly to a structure of a loading coil for antenna tuning.

[0002]

[Prior art]

 Regarding the relationship between the frequency of the wireless communication device and the antenna, in the case of a rod antenna used for a vehicle, an antenna in the HF band of 50 MHz or less for VHF and a common antenna in the 144 MHz band of VHF or the 430 MHz band of UHF. Was never used. A common antenna can be used by setting it to λ / 4 in 144 MHz VHF and to ５ in 430 MHz band of UHF. Fig. 4 shows a rod antenna shared by the high frequency band (144MHz) of VHF and 430MHz of UHF.

On the other hand, in the VHF 50 MHz band to the HF band, antenna tuning is mainly performed at 1 / 4λ. For this reason, a plurality of loading coils were prepared for the rod antenna, and each time the frequency was changed, they were replaced and tuned.

FIG. 3 is a schematic diagram of an antenna corresponding to VHF in the HF band to the 50 MHz band. A motorized variable antenna that tunes the frequency band continuously with one coil instead of using and replacing a plurality of tuning coils of a VHF rod antenna for the VHF band from the HF band to the 50 MHz band has been commercialized in the United States. . USA's HIGH SIE RRA ANTENAS's Model HS-1000 from 3.5 MHz to 30 MHz; J. There is BB-3 of Antenna Company from 3.5 MHz to 54 MHz. Since this antenna cannot support 144 MHz VHF or 430 MHz UHF, it is necessary to prepare an antenna separately when using it.

A loading coil for a low frequency band from HF band to VHF of 50 MHz is of a trap type (a plurality of frequency bands) or a single type (single frequency band). For this reason, in order to continuously tune the frequency from the HF band to the VHF band, a large number of loading coils for the frequency band from the HF band to the low VHF must be provided and replaced. In order to solve this inconvenience, it is better to use a variable coil, but if the variable coil is wound closely, the length of the variable coil can be shortened, but the contact position of the variable coil is only slightly changed. However, the tuning frequency greatly changes, and it is difficult to match the tuning frequency. If the winding of the coil is a sparse coil, the tuning frequency can be finely adjusted, but the coil length becomes long.

[0006]

[Problems to be solved by the invention]

 Conventional antennas that can use one wave from the HF band to a low VHF frequency band, two VHF high frequency bands and two UHF waves use a loading coil for the HF band to a low VHF frequency band for each used frequency band. We replace and use. For this reason, many frequency bands cannot be used unless a loading coil of another frequency band that is not mounted is carried or secured.

In the present invention, the antenna can be tuned without having to use a replacement loading coil for each use frequency band of the VHF band having a low frequency from HF, and further, the high frequency of VHF can be obtained by the integrated antenna. It is an object of the present invention to provide a variable coil for a broadband antenna which can be used as two sets of antennas, a band and a UHF, and whose loading coil can be finely tuned and adjusted with an appropriate length.

[0008]

[Means for Solving the Problems]

 A loading variable coil that changes the tuning frequency by being slid by a drive unit by mounting a rod corresponding to the radio communication frequency HF band to a low VHF frequency band, and a slidably mounted variable coil. A coil housing that has a contact portion that contacts the winding of the variable coil and has the same length as the antenna for the frequency band where λ / 4 and 5 / 8λ are the same in the VHF band and the UHF band in the high frequency band. And a matching section, the variable coil divides the HF band from a low frequency band of VHF into a plurality of frequency bands, and changes the tuning from a high frequency to a low frequency sequentially from the rod antenna side. This is a variable coil for a broadband tuned antenna in which a densely wound portion and a loosely wound portion are alternately formed on a bobbin for each divided frequency band.

[0009]

[Embodiment of the invention]

 FIG. 2 is a schematic diagram showing a broadband tuned antenna using the variable coil of the present invention. The figure will be described. Reference numeral 1 denotes a power supply unit connected to a wireless communication device, and 2 denotes a coil housing unit, which is an antenna element for a high VHF frequency of 144 MHz and a UHF of 430 MHz. 3 is a matching device, 4 is a variable coil for loading, and 5 is a contact portion at a fixed position with respect to a sliding variable coil provided at the tip of the coil housing portion 2 and is in contact with the conductive wire of the variable coil through the contact portion. Thus, the variable coil and the coil housing are electrically connected. 6 is a rod, 7 is a drive part.

In the broadband tuning antenna having the above configuration, the power supply unit 1 uses a coaxial connector to connect a power supply to a transmitting / receiving unit and a driving unit of a wireless communication device by a method of superimposing a high-frequency signal on DC by a well-known circuit. The high-frequency component is separated from the power supply unit 1 and connected to the coil storage unit 2 through the matching unit 3. The matching unit 3 is composed of a matching coil and a capacitor, and the antenna side is matched to the 50Ω inductance of the coaxial cable. On the other hand, the drive unit 7 includes a transmission unit that transmits a linear motion to the variable coil by the rotation of the motor, and the variable coil slides either by rotation or without rotation.

The coil housing 2 has a length of λλ of the VHF in the 144 MHz band, and has a length of ／ λ for the UHF of the 430 MHz band. For VHF from the HF band to the 50 MHz band, a variable coil for loading is connected between the rod 6 and the coil housing 2 so that the center loading method is used, and the tuning frequency is set to 1 / 4λ of the operating frequency.

The variable coil 4 for loading needs to be able to cover from the HF band to the VHF 50 MHz band. For this reason, a coil wound as an inductor is used as a bobbin having a length of about 50 cm. It has a structure in which an uncoated conductor is wound so that the wires do not contact each other. The variable coil 4 for loading is inserted into the coil storage section 2 and attached so that only the contact section 5 contacts.

[0013] Antenna tuning from the HF band to the VHF band of 50 MHz is used by increasing the inductance of the variable coil 4 so that the variable coil 4 is pulled out of the coil housing 2 when the frequency is low in the HF band. . In the case of a high frequency, the lower part of the variable coil 4 is used by being stored in the coil storage section 2. In this tuned state, the inductor in the unused portion of the variable coil 4 is located in the coil storage part which is a part of the antenna, and thus does not affect the antenna tuning.

FIG. 1 is a diagram showing a configuration of a variable coil serving as a center loading used for a broadband antenna. In the drawing, the variable coil 4 is divided into a plurality of frequency bands, and a winding 4b is wound around a bobbin 4a so as to form a densely wound portion and a loosely wound portion, respectively. For example, when the operating frequency is F1 for the low frequency band of HF, F2 is the intermediate frequency of HF, and F3 is the 50 MHz band of VHF, the tightly wound side of the frequency band F3 is the rod 6 shown in FIG. Side. When the frequency range for fine adjustment of F3 is determined, the close-wound coil L3 is wound so as to be at the upper limit of the frequency, and then the close-wound coil L3A in the fine adjustment region is wound. The coil L3 side is the upper limit of the fine adjustment region of the frequency band F3, and the closely wound L2 side which is subsequently wound is the fine adjustment frequency lower limit, and the loosely wound portion L3A is the fine adjustment range of the frequency band F3.

Next, the coil for the frequency band F2 is wound with the close-wound coil L2 following the densely-wound coil L3 and the sparsely-wound coil L3A for the frequency band F3, and the upper limit of the frequency band F2 is finely adjusted. And roll it up. Next, a sparsely wound coil L2A serving as a fine adjustment frequency region of the frequency band F2 is wound. The densely wound coil L2 is the upper limit of the fine adjustment range of the frequency band F2, and the winding end of the loosely wound coil L2A is the lower limit of the fine adjustment range. Following the loosely wound coil L2A, the densely wound coil L1 in the frequency band F1 is wound, and the loosely wound coil L1A is wound in the same manner as the densely wound coil L2 to complete the variable coil. The loosely wound portion L1A is a fine adjustment range of the frequency band F1 where HF is low. Although the frequency band is shown in three stages as described above, the present invention is not limited to this. Considering the 3 MHz band, the 7 MHz band, the 14 MHz band, the 21 MHz band, the 28 MHz band and the VHF 50 MHz band, six sets of frequency bands can be provided, so that a densely wound portion and a loosely wound portion may be appropriately formed.

In the present invention, when the frequency is high, the variable coil 4 is used such that the lower portion of the variable coil 4 is housed in the coil housing 2. As for the variable coil 4 of the loading coil, the coil may be tightly wound or loosely wound as long as an inductor that can tune the antenna to the frequency is obtained. When the frequency and coil diameter are specified, the entire coil should be tightly wound in order to shorten the coil length. However, when only the tightly wound coil is used for the antenna shown in Fig. 2, a slightly variable coil is used. When the position of the contact portion 5 changes with respect to the tuning frequency, the tuning frequency greatly changes, and fine tuning of the tuning frequency cannot be performed. If only a loose coil is used, fine adjustment can be made, but the overall length of the variable coil 4 becomes longer.

When the variable coil of the present invention is used, fine adjustment of the operating frequency can be performed without any problem even if the total length of the variable coil is short in each frequency band. The variable coil 4 forms a sparsely-wound coil and a closely-wound coil corresponding to the above-described frequency on a coil bobbin. By winding at a pitch that does not make contact so that it becomes a winding part, there is no joint between the sparsely wound coil and the closely wound coil, and the bare conductor is wound on the coil bobbin, as compared with the conventional winding method. As a result, it is possible to make contact with all of the sparse and dense coils, and rough tuning of the frequency is possible outside the fine adjustment range.

[0018]

[Effect of the invention]

 In the antenna of the present invention, the loading coil for tuning the rod in accordance with the frequency is densely packed with the sparsely wound part, even if the coil for each of the used frequency bands from the HF band to the VHF band is carried or not secured. A variable coil in which winding portions are formed alternately, and the winding position to be connected by contacting with the contact portion of the coil housing portion is automatically or manually slid and changed, so that the continuous frequency of the HF band to the VHF band is changed. And the VHF / UHF band are integrated using the coil housing, including the matching part where the two waves in the VHF / UHF band are synchronized. Therefore, one wave in the range from the HF band to the VHF band and VHF / UHF Two waves can be used. Since a sparse and dense coil is used for the variable coil, the frequency band used can be finely adjusted, and the overall length of the variable coil can be shortened.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a variable coil for a broadband tunable antenna according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a broadband tuned antenna according to the present invention.

FIG. 3 is a configuration diagram of a conventional variable-type antenna for the HF band to the VHF band.

FIG. 4 is a configuration diagram of a conventional VHF / UHF antenna.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Power supply part 2 Coil accommodation part (V / U antenna element) 3 Matching part 4 Variable coil 4a Bobbin 4b Winding 5 Contact part 6 Rod 7 Driving part

Claims (1)

[Utility model registration claims] 1. A loading variable coil for changing a tuning frequency by mounting a rod corresponding to a radio communication frequency HF band to a low VHF frequency band, and sliding the variable coil by sliding the variable coil. High frequency band VHF with a contact part that contacts the winding of the variable coil and is installed as possible
In a broadband tuning antenna comprising a coil housing formed into a length of an antenna for a frequency band in which λ / 4 and 5 / 8λ have the same length in a band and a UHF band, respectively, and a matching unit, the variable coil comprises: The HF band is divided into a plurality of frequency bands from a low frequency band of VHF, and a tightly-wound portion and a loosely-wound portion of a bobbin are divided for each frequency band from the rod antenna side such that tuning changes from a high frequency to a low frequency. A variable coil for a broadband tuned antenna, wherein the variable coil is formed by alternately forming a variable coil.