KR101022235B1 - Wideband spiral antenna using magneto-dielectric material - Google Patents

Abstract

PURPOSE: A broadband spiral antenna using a magneto-dielectric material is provided to reduce an operating frequency of a high frequency band using a magneto-dielectric material with high dielectric permeability and magnetic permeability, thereby miniaturizing an antenna. CONSTITUTION: A ground surface(120) is made of a conductive plate. A power supply cable(130) is connected to the center of a radiation device through the center of the ground surface. A magnetic dielectric material(140) surrounds a power supply cable. An air layer separates the third magnetic dielectric material(143) from the fourth magnetic dielectric material(144).

Description

Wide band spiral antenna using magnetic dielectric {WIDEBAND SPIRAL ANTENNA USING MAGNETO-DIELECTRIC MATERIAL}

The present invention relates to a wideband spiral antenna (WIDEBAND SPIRAL ANTENNA), and more particularly to a wideband spiral antenna using a magnetic dielectric (MAGNETO-DIELECTRIC MATERIAL).

Conventional spiral antennas include various configurations such as spiral radiating elements, balun circuits, electromagnetic wave absorbers, cavity tapered lines, and the like, when implemented for wideband frequencies. The tapered line achieves 50 ohm impedance matching, and the electromagnetic wave absorber suppresses the backside radiation of the radiation element. The balun circuit performs a function of converting a balance signal into an unbalanced signal.

As such, the broadband spiral antenna has a large volume of matching circuit attached to the rear surface of the radiation element, and a configuration such as a balun circuit, a taper line, and an electromagnetic wave absorber is added. In addition, the additional structure for fixing the balun circuit takes up a large volume.

That is, instead of obtaining broadband characteristics in a spiral antenna, many problems, such as size increase and structure complexity, follow.

An object of the present invention is to provide a broadband spiral antenna using a magnetic dielectric.

A wideband spiral antenna using a magnetic dielectric according to the above object of the present invention includes a spiral type radiation element, a ground plane composed of a conductor plate, and a center for supplying current to the central portion of the radiation element. A feed cable connected to the center of the radiation element through a center of the ground plane, and a magneto-dielectric material formed to surround the feed cable in a predetermined center region between the radiation element and the ground plane; It is configured to. In this case, the predetermined center area may be configured as a space between a predetermined center part operating in a high frequency band of 1 GHz or more of the radiation element and a predetermined center part of a ground plane corresponding to the predetermined center part. Here, it may be configured to further include a printed circuit board (PCB) dielectric provided between the radiation element and the magnetic dielectric. In this case, the magnetic dielectric may be composed of four levels of magnetic dielectric, and the dielectric constant and permeability of the magnetic dielectric may increase from the top to the bottom. On the other hand, when the upper end of the four-stage magnetic dielectric is the first stage and the lower end is the fourth stage, the diameter of the radiation element is 300 mm, the diameter of the first magnetic dielectric is 80 mm, the thickness is 4 mm, The diameter of the two magnetic dielectrics is 80 mm, the thickness is 5 mm, the diameter of the third magnetic dielectric is 80 mm, the thickness is 14 mm, the diameter of the fourth magnetic dielectric is 300 mm, the thickness is 1 mm. Do. On the other hand, the third magnetic dielectric and the fourth magnetic dielectric may be configured to be separated by an air layer. In this case, the spiral type radiation element may be configured as a circular spiral shape or a polygonal spiral type radiation element. In this case, the shape of the top surface of the magnetic dielectric may be configured to match the spiral shape of the radiation element.

According to the broadband spiral antenna using the magnetic dielectric as described above, by using the magnetic dielectric having a high dielectric constant and high permeability by redirecting the operating frequency of the high frequency band, there is an effect of implementing the broadband frequency characteristics. In addition, since various configurations, such as a taper line, a balun circuit, or other structures, are unnecessary, there is an effect of miniaturizing a broadband spiral antenna.

1 is a top configuration diagram of a spiral antenna according to the present invention is applied.
2 is a side configuration diagram of a broadband spiral antenna using a magnetic dielectric according to an embodiment of the present invention.
3 is a graph illustrating the measurement of the reflection loss characteristics of a broadband spiral antenna using a magnetic dielectric according to an embodiment of the present invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. Like reference numerals are used for like elements in describing each drawing.

The terms first, second, A, B, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a top configuration diagram of a spiral antenna according to the present invention is applied.

As shown in Figure 1, the spiral antenna is composed of a spiral-type radiation element. The spiral may have a circular spiral shape as shown in FIG. 1, or may be formed in a triangular or more polygonal shape. On the other hand, the back of the spiral antenna is composed of a ground plane consisting of a conductor plate. Conventionally, not only the ground plane but also a balun circuit and other structures are provided on the rear side, but in the present invention, only the magnetic dielectric and the feed cable are provided between the radiation element on the front side and the ground plane on the rear side. In particular, the magnetic dielectric is configured not to be provided in the entire space between the radiation element and the ground plane, but to be provided only in a predetermined center region between the radiation element and the ground plane.

In the spiral antenna of FIG. 1, when the broadband antenna is configured in a wide band, the central portion of the spiral radiating element is a high band frequency operating part, and the entire or the outer portion of the spiral radiating element is a low band frequency operating part. The magnetic dielectric is formed mainly behind the high band frequency operation part of the radiation element. The magnetic dielectric is configured to have a predetermined permittivity and permeability to lower the operating frequency of the high band frequency of 1 GHz or more to widen the operating frequency band. The outer part of the radiation element, which is an operation part of the low band frequency below 1 GHz, operates without a great loss.

2 is a side configuration diagram of a broadband spiral antenna using a magnetic dielectric according to an embodiment of the present invention.

Referring to FIG. 2, the broadband spiral antenna 100 using the magnetic dielectric according to the present invention is configured to include a radiation element 110, a ground plane 120, a feed cable 130, and a magnetic dielectric 140.

Here, the broadband spiral antenna 100 includes a magnetic dielectric 140 in a predetermined center region between the radiation element 110 and the ground plane 120, and the feed cable 130 radiates through the magnetic dielectric 140. It is configured to supply a current to the center of the element (110). In the present invention, a magnetic dielectric 140 having a very high dielectric constant and permeability is provided in a predetermined center region in which a high band frequency of 1 GHz or more operates, so that the operating frequency band is widened. Thus, unlike the conventional one, it is possible to implement a broadband frequency characteristic without a complicated configuration and to implement the broadband spiral antenna 100 in a small size. Hereinafter, the detailed structure is demonstrated.

First, the radiation element 110 may be configured in a spiral form. Here, the spiral shape may be a circular spiral shape or a polygonal spiral shape of triangle or more. As described above, the radiation element 110 operates in a high frequency band in a predetermined center region and operates in a low frequency band in an entire region or an outer region thereof. At this time, the radio wave radiated from the radiation element 110 is reflected and transmitted from the ground plane 120 on the back.

The ground plane 120 is composed of a conductor plate and reflects and transmits radio waves radiated from the radiation element 110.

The feed cable 130 may be configured to pass through the center of the ground plane 120 to be connected to the center of the radiation element 110 to supply current to the center of the radiation element 110. The feed cable 130 may be connected to the radiating element 110 through another path, but as shown in FIG. 2, the feed cable 130 may be configured to penetrate the center of the magnetic dielectric 140 to be described later. More precisely, it can be seen from the measurement that the magnetic dielectric 140 has better return loss characteristics provided at the feed portion of the radiation element 110.

The magnetic dielectric 140 may be formed to surround the feed cable 130 in a predetermined center region between the radiation element 110 and the ground plane 120. The magnetic dielectric 140 is a material such as epoxy, ceramic, or ferrite, and is configured to have a specific permittivity and permeability. At this time, the dielectric constant is about 10, the permeability is preferably a large value of about 20. If the permittivity and permeability are large, there is a characteristic to lower the operating frequency. However, there is a need to adjust the impedance appropriately because it has the characteristic of increasing the impedance as the opposite benefit.

On the other hand, the shape of the top surface of the magnetic dielectric 140 is preferably configured to match the spiral shape of the radiation element (110). That is, if the radiation element 110 is in the form of a circular spiral, the top surface of the magnetic dielectric 140 is also circular. If the radiation element 110 is in the shape of a polygonal spiral, the top surface of the magnetic dielectric 140 is also polygonal.

On the other hand, the magnetic dielectric 140 may be configured in multiple stages. For example, it may be composed of four stages of magnetic dielectrics, and it is preferable that the dielectric constant and permeability of the magnetic dielectric become lower from the top to the bottom. By allowing the dielectric constant and permeability of the magnetic dielectric close to the radiation element 110 to be a lower permittivity and permeability, there is an effect of preventing the degradation of the reflection loss characteristic of the high band frequency.

In addition, when the magnetic dielectric 140 has a top end near the radiation element 110 among the four stages and a fourth end near the ground plane 140, the diameter of the radiation element 110 is 300 mm. The diameter of the first magnetic dielectric 141 is 80 mm and the thickness is 4 mm. The diameter of the second magnetic dielectric 142 is 80 mm and the thickness is 5 mm. The diameter of the third magnetic dielectric 143 is 80 mm. mm, the thickness is 14 mm, and the diameter of the fourth magnetic dielectric 144 may be 300 mm, and the thickness is 1 mm. When configured with such thickness and diameter, excellent return loss characteristics are shown.

As described above, the magnetic dielectric 140 may be configured in multiple stages, and the composition of the dielectric constant and permeability may be different, and the thickness and diameter may be adjusted to compensate for the impedance degradation generated by increasing the dielectric constant and permeability. That is, the broadband spiral antenna 100 of the present invention not only has a wide band characteristic but also shows an optimum impedance characteristic. It is also compact.

In this case, it is preferable that the third magnetic dielectric 143 and the fourth magnetic dielectric 144 are separated by an air layer. And it is preferable to further include a PCB dielectric 150 provided between the radiation element 110 and the magnetic dielectric 140. In this case, the PCB dielectric 150 may be made of epoxy. The spacing between the radiating element 110 or the ground plane 120 and the magnetic dielectric 140 may be higher than that of the high dielectric constant and permeability of the magnetic dielectric 140 in contact with the radiating element 110 or the ground plane 120. It exhibits excellent return loss characteristics. On the other hand, spaced apart through the PCB dielectric 150 exhibits better return loss characteristics than the first magnetic dielectric 141 does not contact the radiation element 110. In particular, the PCB dielectric 150 functions to reflect short-wave propagation from the first magnetic dielectric 141 at a predetermined center portion of the radiation element 110 operating in the high frequency band. That is, the first magnetic dielectric 141 performs the function of the reflecting plate. This brings about a high efficiency radiation characteristic effect.

3 is a graph illustrating the measurement of the reflection loss characteristics of a broadband spiral antenna using a magnetic dielectric according to an embodiment of the present invention.

3 shows reflection coefficient values for each frequency band. According to the present invention, since the reflection loss is lowered over the wide band, it can be seen that the spiral antenna 110 operates in the wide band. Operating at frequencies above approximately 260 MHz, the size is reduced by 16% in diameter and 83% in height (thickness) compared to the 2040 model of microwave engineering corporation (MEC), a product of the same frequency band. It works.

Although described with reference to the embodiments above, those skilled in the art will understand that the present invention can be variously modified and changed without departing from the spirit and scope of the invention as set forth in the claims below. Could be.

100: broadband spiral antenna
110: radiation element
120: ground plane
130: feed cable
140: magnetic dielectric
141: first magnetic dielectric
142: second magnetic dielectric
143: third magnetic dielectric
144: fourth magnetic dielectric
150: PCB dielectric

Claims (8)

Radiation elements in the spiral form;
A ground plane composed of a conductor plate;
A feed cable connected to the center of the radiation element through a center of the ground plane to supply current to the center of the radiation element;
A magnetic dielectric (magneto-dielectric material) formed to surround the feed cable in a predetermined center region between the radiation element and the ground plane,
The predetermined center region is a space between a predetermined center portion operating in a high frequency band of 1 GHz or more of the radiation element and a predetermined center portion of a ground plane corresponding to the predetermined center portion. delete The method of claim 1,
Broadband spiral antenna using a magnetic dielectric further comprising a printed circuit board (PCB) dielectric provided between the radiation element and the magnetic dielectric. The method of claim 3, wherein the magnetic dielectric,
Broadband spiral antenna using a magnetic dielectric, consisting of four stages of magnetic dielectric, characterized in that the dielectric constant and permeability of the magnetic dielectric increases from top to bottom. The method of claim 4, wherein when the upper end to the lower end of the four-stage magnetic dielectric are the first end, the second end, the third end, and the fourth end,
The diameter of the radiation element is 300 mm,
The diameter of the first magnetic dielectric positioned in the first end is 80 mm, the thickness is 4 mm,
The diameter of the second magnetic dielectric positioned in the second end is 80 mm, the thickness is 5 mm,
The third magnetic dielectric positioned in the third end has a diameter of 80 mm and a thickness of 14 mm,
The fourth magnetic dielectric positioned at the fourth end has a diameter of 300 mm, the thickness is 1 mm wide broadband spiral antenna using a magnetic dielectric. The method of claim 5, wherein the third magnetic dielectric and the fourth magnetic dielectric,
Broadband spiral antenna using a magnetic dielectric, characterized in that separated by the air layer. The method of claim 6, wherein the spiral-type radiation element,
A broadband spiral antenna using a magnetic dielectric, characterized in that the radiation element of the circular spiral shape or polygonal spiral shape. The shape of the top surface of the magnetic dielectric of claim 7,
Broadband spiral antenna using a magnetic dielectric, characterized in that the spiral shape of the radiation element.

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