Patent Grant
11251532
The present invention relates to a small dipole antenna, and more particularly, to a small dipole antenna provided with a balun, a meander line and a cap to cover a whole of the meander line, wherein the meander line is provided on both sides of the dipole antenna so as to reduce the overall size of the dipole antenna.
Broadband antennas widely used in the art include biconical antennas, elliptical monopole antennas, flat-shaped diamond antennas, notch antennas, bow tie type antennas that can be directly installed on PCBs, rigid horn antennas, conical horn antennas, forward coaxial horn antennas, Lomvik antennas, logarithmic antennas, spiral antennas, and the like.
Thereamong, an antenna for electromagnetic interference (EMI) evaluation is often used in a defined space such as the inside of a building, a hull, an airplane, a vehicle, etc. However, the conventional broadband antenna described above may use a thick element or may have a broadening structure in a triangular form, a structure in which a transmission line itself spreads, a structure in which elements with different sizes are arranged, or a structure in which elements are arranged in a round form. Therefore, it is difficult to carry the antenna due to very large volume thereof, thus causing a problem of difficulty in using the same for measurement of electromagnetic waves.
Further, for an antenna for measuring electromagnetic waves, it is important for the antenna to be affected as little as possible by the surrounding environment, in particular, ground conditions. For this purpose, a dipole antenna is preferably used rather than a monopole antenna.
Therefore, there is a need for development of a small dipole antenna which a new structure having a reduced size, which is easy to use and can accurately measure an electromagnetic environment.
The present invention has been devised to meet the requirements as described above, and an object of the present invention is to provide a small dipole antenna by reducing overall size of a dipole antenna structure so as to easily implement functions of the antenna in measurement of electromagnetic wave performance regardless of an environment in which the antenna is used.
The object of the present invention is not limited to that mentioned above and other objects not mentioned herein will be clearly understood from the following description by those skilled in the art.
A small dipole antenna according to an embodiment of the present invention to solve the above problem may be provided together with a configuration of: a connector formed on one end of the dipole antenna; a balun formed on one side of the connector; a first meander line, one side of which is fixed to one end of the balun; a second meander line, one side of which is fixed to one end of the balun; a filling member to fill a space of a bent portion of a curved portion in the first meander line or the second meander line; and a cap to cover the first meander line and the second meander line.
In this case, a bundle connected to the balun, that is, a bundle including the first meander line, the second meander line, a cover, etc. is called an antenna unit.
The balun and the antenna unit are preferably coupled with a knob or a screw.
The first meander line or the second meander line may extend not to be parallel to a heading (or traveling) direction of the balun with respect to the balun, and may be provided with at least one bent portion or curved portion.
One or more filling members may be provided, and the filling members preferably have the same or different sizes.
The cap may include a switch part to open or close a predetermined area covering the first meander line or the second meander line.
In this case, the small dipole antenna may further include a short stub to connect the first meander line and the second meander line.
With regard to the small dipole antenna according to an embodiment of the present invention, the configuration of the meander line extending in both sides with respect to the balun, as well as the filling member in a predetermined size used to fill a gap between the meander lines, may obtain resonance frequency adjustment characteristics. Further, adding a short stub between the meander lines may achieve impedance matching. At the same time, an overall size of the dipole antenna structure can be desirably reduced to ensure easy antenna operation regardless of external conditions when determining electromagnetic wave performance.
Effects of the present invention are not limited to those mentioned above, and other effects not mentioned herein will be clearly understood from the following description by those skilled in the art.
Objects and effects of the present invention and technical configurations for achieving the same will be apparent with reference to the embodiments described later in detail in conjunction with the accompanying drawings. In describing the present invention, if it is considered that description of known functions or configurations may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. The terms described later are terms defined in consideration of structures, roles, functions, and the like in the present invention, which may vary according to intentions of users or operators or customs in the art.
However, the present invention is not limited to the embodiments disclosed below but may be implemented in various forms. The present embodiments are merely provided to complete the disclosure of the present invention, and to fully inform the scope of the invention to those skilled in the art. Therefore, the present invention is only defined by the range described in the appended claims. Accordingly, the definition should be made based on the contents throughout the specification.
In the whole specification, when a part is said to “include” a certain component, it means that the part may further include other components without excluding the same unless specifically stated otherwise.
The present invention provides a dipole antenna having a frequency band of 146 to 174 MHz, which is available in the international standard for immunity test (ISO11452-9) [1] to verify malfunction by applying the radio waves generated from portable devices such as clock radios, mobile phones, Wi-Fi, etc. used in the vehicle to automobile electronics.
The antenna presented in the current standard is a vertical mode monopole type helical antenna, and may have resonance frequency and radiation pattern possibly varying under influences of setup and the surrounding ground. Therefore, in order to overcome this problem, the inventor of the present invention has devised a folded dipole antenna which is less affected by the ground.
ISO11452-9 international standard is used in a tolerance test, that is, immunity assessment that determines malfunction by applying radio waves generated from various portable transmitters used in the vehicle, for example, clock radios, mobile phones, Wi-Fi, etc., to automobile electronics, and is currently modified and utilized by North American vehicle manufacturers (GM, Ford, Daimler), European vehicle manufacturers (Volkswagen, Volvo, Renault, etc.), and Japanese vehicle manufacturers (Nissan, etc.). Component suppliers for these vehicle manufacturers should perform immunity assessment.
ISO11452-9 standard proposes an evaluation antenna for each frequency and a vertical mode monopole type helical antenna in the frequency band of 146 to 174 MHz.
However, since the characteristics of the monopole antenna are influenced by the surrounding ground and are also affected by a coaxial cable for feeding, test setup, EUT and a position of the measurement instrument, not only are antenna characteristics such as RL (Return Loss) and VSWR but also resonance frequency and field (radiation pattern) are changed. As a result, the desired E-field strength cannot be acquired at the corresponding frequency.
In order to solve such problems, the present invention intends to develop and propose a dipole antenna which is independent of GND of antenna feeding and is applicable to a surrounding ground environment such as a GND table.
The dipole antenna of the present invention may apply a miniaturization technique to a typical dipole antenna. Each pole in the antenna is designed as a meander according to the miniaturization technique, and a frequency adjustment point is designed as a physical length of the meander. In this regard, a configuration of the meander has been designed such that vector directions or current are orthogonal to each other so as to minimize current loss while both ends are covered with caps.
In order to reduce capacitance caused by the meander and the cap, a short stub may be added to a beginning part of the pole, thus performing impedance matching.
Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail.
The present invention provides a small dipole antenna including a balun, a meander line and a cap to entirely cover the meander line, wherein the meander line is provided on both sides of the dipole antenna in order to decrease an overall size of the dipole antenna. For comparison, the conventional dipole antenna shown in
The conventional dipole antenna 100 shown in
First, the antenna structure 110 may be made of a material containing a metal component, and the above metal component may constitute a metal workpiece or an electronic circuit board. The electronic circuit board may be composed of glass, ceramic, synthetic resin, a printed circuit board (PCB) and the like, and the antenna made of a metal component may include two poles based on the characteristics of the dipole antenna, wherein both poles preferably have a symmetrical structure.
The two poles are named first and second antennas 161 and 162. The first antenna 161 and the second antenna 162 may be formed of a metal material, and may be provided to be in contact with the electronic circuit board or the dielectric body 180 on one face and the other face thereof.
Specifically, the first antenna 161 and the second antenna 162 are formed on one surface of the electronic circuit board and spaced apart from each other at a predetermined interval. The first antenna 161 and the second antenna 162 may be formed symmetrically with respect to the center of the electronic circuit board, and may be made of a conductor such as copper, bronze, gold, and silver. The first and second antennas 161 and 162 may be manufactured in a desired pattern by applying a general method such as printing, lithography and etching to one surface of the electronic circuit board or the dielectric body 180, or a printed circuit board (PCB). Alternatively, a printed circuit board (PCB) may be adopted and mounted on the dielectric body 180 or the electronic circuit board.
Meanwhile, each of the first and second antennas 162 may further include a first feed member 1 and a second feed member 2. Specifically, each of the first feed member 1 and the second feed member is connected to a first antenna body 151 or a second antenna body 152 and extends from the connected antenna toward the other antenna, wherein both feed members are spaced apart from each other at a predetermined interval.
That is, such a configuration in which the first feed member extends toward the second antenna body 152 and the second feed member extends toward the first antenna body 151, wherein these feed members are formed on the electronic circuit board while being spaced apart from each other at random intervals, can be confirmed. As shown in the drawings, it can be seen that the dipole antenna extends vertically in a considerable length from a heading direction of the enclosure 120 and the handle 130, and therefore, it can be confirmed that the above configuration has difficulty in achieving miniaturization.
Hereinafter, the dipole antenna of the present invention, which is different from the conventional dipole antenna of
Referring to
As shown in
In this case, when a circuit parallel to the ground is coupled to an amplification circuit having one grounded end, the balun 400 may prevent ground balance of the parallel circuit from collapsing or may refer to a matching transformer, which is used to connect the ground-parallel circuit to an unbalanced circuit such as a coaxial cable in a very high frequency (VHF) transmission circuit. Further, the balun is a portmanteau of “balanced” and “unbalanced”, and may have an impedance conversion function based on features of the balun 400.
According to a configuration of the knob 300, effects of easily attaching and detaching the antenna unit through a simple structure, which is easy to couple the antenna unit and the balun 400 or the like, can be achieved.
Referring to
A portion of the cap 200 to be opened and closed is called a switch part 210. Although the switch part 210 is shown as empty in
The switch part 210 can open and close a predetermined portion of the first meander line 610 or the second meander line 620, thereby enabling effects of adjusting resonant frequency characteristics of the dipole antenna.
As shown in
Referring to
More specifically, the first meander line 610 or the second meander line 620 extends not to be parallel to a heading direction of the balun 400 with respect to the balun 400, and is preferably provided with at least one bent portion or curved portion.
Further, the filling member 640 is made of the same metal material as the meander line. Specifically, at least one filling member is provided in the same or different size. Specifically, resonance frequency characteristics of the small dipole antenna can be adjusted depending on the number and size of the filling members.
In addition, a short stub 630 connecting the first meander line 610 and the second meander line 620 may be further included so as to easily perform impedance matching through a simple structure.
As shown in
Alternatively, the bent portion A of the small dipole antenna shown in
When comparing the dipole antennas between
The dipole antenna in
Table 1 below shows antenna characteristics obtainable in five types of antennas shown in
As shown in
In
As described above, although embodiments of the present invention have been described, those skilled in the art would diversely alter or modify the present invention by adding, changing of deleting components within the range without departing from the spirit of the present invention described in the appended claims. Further, it should be understood that such alteration or modification is within the scope of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2018-0054411 | May 2018 | KR | national |
| 10-2018-0172957 | Dec 2018 | KR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2019/005578 | 5/9/2019 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2019/216672 | 11/14/2019 | WO | A |
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| 20070188399 | Rickenbrock | Aug 2007 | A1 |
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| Number | Date | Country |
|---|---|---|
| 2008-098769 | Apr 2008 | JP |
| 01-48860 | Jul 2001 | WO |
| 2013-099811 | Jul 2013 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 20210194137 A1 | Jun 2021 | US |
