KR20060101256A - Micro-strip antenna for satellite dmb terminal and terminal having the antenna - Google Patents

Abstract

According to the present invention, in a cylindrical quadrifilar helix antenna formed by spiraling four strip lines, a ground plane is formed at a feed portion, and the length and width of the feed line of the strip line are adjusted to be adjacent to each other. By having a phase difference of 90 degrees between the radiators, the present invention relates to a microstrip antenna for a satellite DMB and a terminal having the same, which can maintain the phase difference without using an external circuit and are easy to manufacture.

The present invention relates to a microstrip antenna for a satellite DMB terminal including a dielectric substrate, four radiators spirally formed on the dielectric substrate, and a feeding part, wherein each of the radiators having a predetermined distance between adjacent radiators has the same length and width. A strip line having a quarter wave conversion strip line connected between a feeder and a first radiator, for feeding a signal such that there is a 90 degree phase difference between the adjacent radiators; A first feed path connected between the first copy and the second copy, a second feed path connected between the second copy and the third copy, and a third feed path connected between the third copy and the fourth copy; And the quarter wavelength conversion strip line and the first, second and third feed paths each have a length and a width different from each other. Includes a ground plane configured.

Microstrip, Helix, Antenna, Satellite, DMB, Quad Refiller, Dielectric

Description

Microstrip antenna for satellite DMB terminal and terminal having same {Micro-Strip Antenna for Satellite DMB Terminal and Terminal Having The Antenna}

1 is a perspective view of a microstrip antenna for satellite DMB terminal according to the present invention.

2 is an exploded view of the antenna shown in FIG. 1 in accordance with the present invention;

3 is a side view of the antenna shown in FIG. 1 in accordance with the present invention;

4 is a graph showing the return loss characteristics according to the frequency of the antenna according to the present invention.

5 is a graph showing the radiation pattern characteristics at 2.638 GHz of the antenna according to the present invention.

* Explanation of symbols on the main parts of the drawing

11: copy 12: dielectric substrate

13: ground plane 21: antenna part

22: feed part 23: feed line

24: 1/4 wavelength conversion path 25, 26, 27: feed path

The present invention relates to a microstrip antenna for a satellite digital multimedia broadcasting (DMB) terminal, and more particularly, in a cylindrical quadrifilar helix antenna formed by spirally copying four strip lines. The ground plane is formed on the part, and the length and width of the feed line of the strip line are adjusted to have a phase difference of 90 degrees between adjacent radiators, so that the phase difference can be maintained without using an external circuit and the manufacturing is simple with a simple structure. The present invention relates to a microstrip antenna for satellite DMB and a terminal having the same.

So far, broadcasting and communication have been understood as different concepts. Traditionally, broadcasting has established a transmission network using telecommunication facilities, and through this, unidirectional delivery of a broadcast program including voice and video to an unspecified number. On the other hand, communication means establishing a bidirectional communication network and performing bidirectional transmission and reception between service users, and the contents have mainly been voice services.

However, the boundaries between broadcasting and telecommunications are being broken down by the development of information and communication technologies, the development of services, the deregulation of regulations and the promotion of competition. The convergence of broadcasting and communication is developing toward combining DMB, which is emerging as a new next-generation multimedia service, and existing mobile communication, and, in just a few years, a personal interactive media can be seen through such a combination. It is expected. Accordingly, there is a demand for developing an antenna that can be used for a mobile communication terminal provided with a DMB service.

In order for the antenna to receive quality service from the satellite, it meets many requirements such as high quality circular polarization characteristics, wide beam width, high front to back ratio, and minimization of performance variation according to ground and terminal location and shape. Should be. The antennas used to satisfy these conditions relatively well are used as quadrifilar helix antennas, non-filler bifilar conical spiral antennas, and quadrifilar conical antennas. Etc.

Among these, the present invention relates to a quad refiller helix antenna. Quad-refiller helix antennas are described by IEEE "Resonant Quadrifilar Helix", Voi. It was first introduced in AP-17, May 1969, pp. 349-351.

Quad refiller helix antenna is formed by four stripe-shaped spirals to form a spiral. The helical arrangement includes electrically conducting strip lines of pitch angle P and length L for cylinders of any diameter. The operating characteristics of the antenna are determined by the geometrical properties of the helix, the number of interconnections between the conductive electrodes and the feed arrangement. Such quadrifilter helix antennas are presented in Korean Utility Model Publication No. 20-379405.

Utility Model Registration No. 20-379405 has a main body made of a cylindrical dielectric, four radiating elements formed on the circumferential surface of the main body, and formed on the first end surface of the main body and between the four radiating elements. A feeder for providing a signal having a phase difference of degrees, a radiation element formed at a second cross section of the main body, and receiving a signal having a phase difference of 0 degrees and 180 degrees, and a signal having a phase difference of 90 degrees and 270 degrees The present invention relates to a quad refiller helix antenna having a connection portion connecting the received radiating elements to each other.

In the prior art, the power supply unit has one end connected to the feed line and the other end connected to the first radiation element to provide a signal having a phase difference of 90 degrees to the four radiation elements, thereby receiving a first input signal applied from the feed line. A first feed arm that is input and an extension portion formed at one end of the other end of the first feed arm, and whose end is connected to a second radiation element, a signal having a phase difference of 90 degrees with the first input signal to the second radiation element; A first feeding element comprising a first meander line formed to a predetermined length to be applied; A second feed arm having one end connected to a feed line and the other end connected to a third radiation element, the second feed arm receiving a second input signal applied from the feed line, and extending from one side of the other end of the second feed arm and being terminated And a second feed element connected to the fourth radiation element, the second feed element having a second meander line having a predetermined length to apply a signal having a phase difference of 90 degrees with the second input signal to the fourth radiation element.

However, such a conventional quadruple filler helix antenna has a disadvantage that the feeder is formed on the upper surface or the lower surface of the cylindrical dielectric, and the diameter of the cylindrical dielectric is large as a whole because a separate structure for grounding is required. However, there is a disadvantage that the performance of the antenna is not good because the gain of the antenna is low.

The present invention has been proposed to solve the problems of the prior art as described above, and the present invention provides a cylindrical quadrifilar helix antenna in which spirals of four strip lines are spirally formed. A ground plane is formed, and the length and width of the feed line of the strip line are adjusted to have a 90 degree phase difference between adjacent radiators, so that the phase difference can be maintained without using an external circuit and the satellite DMB is easy to manufacture with a simple structure. An object of the present invention is to provide a microstrip antenna and a terminal having the same.

Other objects and advantages of the present invention can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

According to an aspect of the present invention, there is provided a microstrip antenna for a satellite DMB terminal including a dielectric substrate, four radiators spirally formed on the dielectric substrate, and a feeding portion, wherein the dielectric strips have a predetermined distance between adjacent radiators. Each of the radiators includes strip lines having the same length and width, wherein the feeding portion is a quarter wavelength connected between the feeding portion and the first radiator for feeding a signal such that there is a 90 degree phase difference between the adjacent radiators. A conversion strip line, a first feed path connected between the first copy and the second copy, a second feed path connected between the second copy and the third copy, and connected between the third copy and the fourth copy And a third feed path, wherein the quarter wavelength conversion strip line and each of the first, second, and third feed paths are of a length and width. It is different, characterized in that it comprises a ground plane formed on the feed portion.

In addition, a terminal according to the present invention, a satellite DMB terminal comprising an antenna and a receiving module for receiving a satellite DMB signal, the antenna comprising: a dielectric substrate; Four radiators that are spirally patterned on the dielectric substrate and spaced at regular intervals, each of the four radiators including strip lines having the same length and width; And a feeding portion for feeding a signal such that there is a phase difference of 90 degrees between the adjacent radiators, wherein the feeding portion comprises a quarter wavelength conversion strip line connected between the feeding portion and the first radiator, and the first radiator; A first feed path connected between a second copy, a second feed path connected between the second copy and the third copy, and a third feed path connected between the third copy and the fourth copy, wherein 1 A ground plane formed at the same position as the feeding portion on the upper and / or lower surfaces of the / 4 wavelength conversion strip line and the first, second and third feeding paths, respectively, having different lengths and widths; Characterized in that it comprises a.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, whereby those skilled in the art may easily implement the technical idea of the present invention. There will be. In addition, in describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used to refer to the same components, even if displayed on different drawings.

1 is an overall perspective view of a microstrip antenna for a satellite DMB terminal according to the present invention, Figure 2 is an exploded view of the antenna shown in Figure 1 according to the present invention, Figure 3 is a view of the antenna shown in Figure 1 according to the present invention Side view.

The microstrip antenna for satellite DMB terminal according to the present invention uses a quadrifilar helix antenna to generate a high quality circular polarization essential for DMB broadcasting reception, and to provide a miniaturization of the entire antenna system, A micro strip line feeding structure using a quarter wavelength conversion method is used. Since the microstrip feeding structure is easy to calculate impedance and match and has a relatively large ground plane, the microstrip feeding structure has an advantage of being less externally affected even when the antenna is located close to the portable terminal. In addition, the feeding structure according to the present invention can be implemented on the dielectric substrate that can be refracted, and the size and weight of the antenna system can be reduced, resulting in easy application to a portable terminal.

In FIG. 2, the antenna according to the present invention is largely composed of a feed portion 22 consisting of an antenna portion 21 and a microstrip. The antenna portion 21 comprises a dielectric substrate 12 and a copy 11 of four conductive strip lines formed on the dielectric substrate 12.

The antenna according to the present invention has a cylindrical shape, and four cylindrical bodies 11 of conductive microstrip lines are helically patterned on the cylindrical dielectric substrate 12. Patterning the micro strip line on the dielectric substrate 12 is a well-known technique and a detailed description thereof will be omitted.

The dielectric substrate 12 according to the present invention is a polyimide laminate substrate having a thickness of 0.05 mm, and the dielectric constant of the dielectric substrate 12 is 4.0. Further, each of the four copies 11 has a width and a length of 1 mm and 48.87 mm, respectively, and an interval between each copy 11 is 7 mm, and each copy has the same length, width and spacing. Further, each copy 11 has the same pitch angle. Furthermore, the antenna according to the present invention has a form in which the ends of each radiator are open, and as shown in FIGS. 1 and 2, the radiant ends in the opposite directions of the feeding portion 22 are all connected by a micro strip line. .

The antenna according to the present invention uses a 50 Ω microstrip feeder 23, and the feeder part comprises a ground plane 13 having a width of 28 mm and a length of 9 mm, respectively. That is, in the present invention, the ground plane 13 is provided together with the feeding portion of the antenna, and the ground plane 13 may be formed to be equal to the developed horizontal length (28 mm) of the dielectric substrate, and the upper surface of the dielectric substrate. And / or on the bottom surface. In addition, the ground plane 13 is formed of a material different from the feed line, and is made of a material that serves as a ground and does not pass through a signal. That is, when the ground plane 13 is a conductive material, the signal flowing into the feed line flows to the ground plane 13 so that the signal does not flow. Thus, the ground plane is manufactured by using a material different from the feed line to prevent this.

In the present invention, the feed from the power supply 23 to the first copy is matched using a quarter wave transformer strip line 24. In addition, in order to feed each radiator of the antenna with the same size and to have a phase difference of 90 degrees, the lengths and widths of the feed paths 25 to 27 from the first radiator to the fourth radiator are adjusted differently. The quarter wavelength conversion strip line 24 is continuously connected to the third feed path 27. In a preferred embodiment of the present invention, the quarter wavelength converting strip line 24 has a length of 15.38 mm and a width of 0.435 mm, and the first feed path 25 has a length of 14.75 mm and a width of 1.19 mm. . In addition, in a preferred embodiment of the present invention, the first feed path 26 has a length of 15.06 mm and a width of 0.69 mm, and the third feed path 27 has a length of 15.97 mm and a width of 0.22 mm.

The present invention uses a separate external circuit by adjusting a length and a width of a feed path that transmits a signal to each radiator differently, so that a signal having a phase difference of 90 degrees can be transmitted between adjacent radiators. It is possible to maintain a phase difference of 90 degrees without doing so. Furthermore, in the present invention, by providing the ground plane 13 in the feed portion, the gain can be improved while making the antenna more compact. The antenna according to the present invention as described above is mounted on the satellite DMB receiving terminal.

4 is a graph showing the return loss characteristics of the antenna according to the present invention.

The quad refiller helix antenna according to the present invention is designed to resonate at 2.638 GHz.

The circular polarization characteristics and the hemispherical pattern characteristics of the antenna are made by changing the feed path length and width between the four radiators in the feed portion, and a quarter wave conversion strip line is used for impedance matching.

5 shows a radiation pattern of an antenna according to the present invention having such a feature. The measured radiation pattern shows hemispherical radiation characteristics and has a half-power beamwidth of 90 or more.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

As described above, the antenna according to the present invention has a phase difference of 90 degrees between adjacent radiators by adjusting the feeding path length and width between four radiators in the feeding portion, and feeds using a quarter wavelength conversion strip line. Since impedance matching is easy and a relatively large ground plane is formed at the feed portion, external influence is less affected even when the antenna is located close to the portable terminal. In addition, the present invention can be implemented on a dielectric substrate that can be refracted and the size and weight of the antenna system can be reduced, resulting in easy application to a portable terminal.

Claims (11)

A microstrip antenna for a satellite DMB terminal comprising a dielectric substrate, four radiators spirally formed on the dielectric substrate, and a feeding part. Each of said copies having a constant spacing between adjacent copies comprises strip lines of equal length and width, The feed portion is a quarter wavelength conversion strip line connected between the feed portion and the first radiation, and between the first radiation and the second radiation to feed a signal such that there is a 90 degree phase difference between the adjacent radiations. A first feed path connected, a second feed path connected between the second and third radiators, and a third feed path connected between the third and fourth radiators, wherein the quarter-wave conversion strip A line and each of the first, second, and third feed paths have different lengths and widths, And a ground plane formed on the feed portion. The method of claim 1, And the ground plane is formed on the top surface and / or the bottom surface of the dielectric substrate. The method of claim 2, And the ground plane is formed of a material that does not transmit a signal different from that of the strip line of the feed portion. The method of claim 2, And the ends of each of the radiators in the opposite directions to the feed portion are all connected by strip lines. The method of claim 4, wherein Wherein each of the radiators has a width of 1 mm and a length of 48.87 mm, and the spacing between the radiators is 7 mm. The method of claim 2, And the ground plane has the same horizontal length as the horizontal length of the dielectric substrate. The method of claim 2, And said quarter-wave conversion strip line has a length of 15.38 mm and a width of 0.435 mm. The method of claim 2, And the first feed path has a length of 14.75 mm and a width of 1.19 mm. The method of claim 2, And the second feed path has a length of 15.06 mm and a width of 0.69 mm. The method of claim 2, And said third feed path has a length of 15.97 mm and a width of 0.22 mm. In the satellite DMB terminal comprising an antenna and a receiving module for receiving a satellite DMB signal, The antenna, Dielectric substrates; Four radiators that are spirally patterned on the dielectric substrate and spaced at regular intervals, each of the four radiators including strip lines having the same length and width; And A feeding part for feeding a signal such that there is a 90 degree phase difference between the adjacent radiators, The feed portion may comprise a quarter wavelength conversion strip line connected between a feed portion and a first copy, a first feed path connected between the first copy and a second copy, and connected between the second copy and the third copy. A second feed path and a third feed path connected between the third and fourth radiators, wherein the quarter wavelength conversion strip line and the first, second, and third feed paths each have a length and a length; Different widths, And a ground plane formed on a top surface and / or a bottom surface of the dielectric substrate at the same position as the power feeding portion.

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