KR100278315B1 - Dual polarized microstrip antenna with dual feed structure capable of two-dimensional arrangement - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

A dual polarized microstrip antenna with a dual feed structure that can be expanded in a two-dimensional array.

2. Challenges to the Invention

In order to increase the gain of the antenna, it provides a dual feed structure and antenna design algorithm having a structure that can be extended to a two-dimensional array.

3. Summary of solution of invention

According to the present invention, the two feeds are extended by using a dual feed method using a microstrip line feeding method, a feed method combining a via hole and a microstrip line, or a dual feeding method using a microstrip line feeding method and a slot-coupled feeding method. Fixed the problem of overlapping feeder lines and increased volume.

4. Important uses of the invention

The present invention can be applied to an antenna for an indoor base station that can obtain a polarization diversity gain, and is also applied to a small-sized, light-weight, portable and easy-to-use transmission / reception antenna that can replace a conventional parabolic antenna.

Description

Dual polarized microstrip antenna with dual feed structure capable of two-dimensional arrangement

The present invention relates to a dual-polarized microstrip antenna, and more particularly, to a dual polarized microstrip antenna having a dual-fed structure capable of a two dimensional array.

Recently, as mobile communication services become full-fledged, efforts are being made to effectively use a variety of high-quality services. In particular, users need a base station that is lighter, easier to move and install, and can receive various services. Therefore, according to these demands, the antenna, which is a core part of the communication device, is also required to have small size, light weight and high efficiency.

For example, in the case of a high frequency use scheme of 1.7 to 1.9 GHZ bands such as PCS, IMT-2000, the radio wave reach is relatively shorter than the existing service schemes, and thus requires more base stations. Therefore, miniaturization of the base station antenna located closest to the consumer is essential.

Accordingly, the development of microstrip antennas, which are easy to miniaturize and lighten, is being actively developed. In particular, there are many reflectors and obstacles such as walls and ceilings having various dielectric constants such as indoors, and at the same time, they have limited space. In this paper, dual-polarized antennas with polarization diversity gain have been studied.

However, in the case of using the microstrip antenna in the indoor space, it is necessary to arrange various antennas according to the shape of the indoor space, and also in the case of the conventional double feed method used to obtain the dual polarization characteristic, two dimensional array (two dimensional) Since it is impossible to expand to an array, a double feed structure that can be extended to a two-dimensional array is urgently needed.

In addition, conventionally, in determining the width and length of the dual polarized microstrip antenna, the antenna must be designed using an experiment or a simulator. There is an urgent need for a way to design the system.

Accordingly, an object of the present invention is to provide a dual polarized microstrip antenna having a dual feed structure that is expandable in a two-dimensional array and which can be obtained at a single resonant frequency. do.

Another object of the present invention is to provide a method for designing a dual polarized microstrip antenna having a dual feed structure that is expandable in a two-dimensional array and can obtain a dual polarization characteristic at a single resonant frequency in order to solve the needs as described above. have.

In addition, in order to solve the above requirements, a computer having a double feed structure that is expandable in a two-dimensional array and a program for realizing a dual polarized microstrip antenna design capable of obtaining dual polarized wave characteristics at a single resonant frequency is provided. It is another object of the present invention to provide a readable recording medium.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a diagram for explaining a dual polarized microstrip antenna structure according to a first embodiment of the present invention.

2A and 2B are views illustrating a power feeding method in which a via hole and a microstrip line in FIG. 1 are mixed.

3 is a view for explaining the structure of the dual polarized microstrip antenna of the second embodiment according to the present invention;

Figure 4 is an equivalent view of the dual polarized microstrip antenna of the present invention at powering only with a microstrip line.

5 is an equivalent view of the dual polarized microstrip antenna of the present invention at the time of feeding with only the via-hole feeding portion;

Figure 6 is a view for showing a dual polarization characteristics when feeding at the same time in the two feeder for the dual polarized microstrip antenna according to the present invention.

7 is a design flow diagram of a dual polarized microstrip antenna according to the present invention.

8 shows an extension of the present invention to a two dimensional array antenna;

* Explanation of symbols for the main parts of the drawings

A: first microstrip substrate B: second microstrip substrate

11, 21, 31, 41, 51, 61: radiating element

12, 32, 42, 52, 62: microstrip lines

13, 53, 63, 83: Via hole 14, 54, 64, 84: Via hole feeder

22: dielectric 23: ground plane

24: feeding part 25: proof

26: relief hole 33: slot

34 slotted feeder 81 microstrip antenna

82: microstrip line feeder

A dual polarized microstrip antenna of the present invention for achieving the above object, the first microstrip substrate for mounting the radiating element and the first feeder; A second microstrip substrate for mounting a second feed section formed of a microstrip line; Means for coupling a radiating element on said first microstrip substrate with a second feeder on said second microstrip substrate, said first microstrip substrate being positioned thereon and said second microstrip substrate beneath it. It is characterized in that the position and joining.

In addition, the means for coupling the radiating element and the second feeder in the configuration is characterized in that the first feeder and the vertical structure with each other.

In addition, a method of designing a dual polarized microstrip antenna according to the present invention for achieving the above objects, the first step of initializing the width and length of the antenna to a half-wavelength value; A second step of calculating the input impedance of the microstrip antenna using the transmission line model and changing the length and width of the antenna such that the imaginary part of the input impedance becomes '0' while calculating the input impedance of the antenna at the resonance frequency; A third step of outputting a width and a length of the antenna obtained through the second step; And a fourth step of obtaining a feed point (xf) having an input impedance equal to the characteristic impedance of the via hole while gradually changing the starting feed point (xf) from the edge of the patch to find the via hole feed point. .

A dual polarized microstrip antenna design system having a microprocessor, the system comprising: a first function of initializing a width and a length of an antenna to a half wavelength value; A second function of calculating an input impedance of the microstrip antenna using a transmission line model and changing the length and width of the antenna such that the imaginary part of the input impedance becomes '0' while calculating the input impedance of the antenna at the resonance frequency; A third function of outputting a width and a length of the antenna obtained through the second function; And a program for realizing a fourth function of finding a feed point (xf) having an input impedance equal to the characteristic impedance of the via hole while gradually changing the starting feed point (xf) from the edge of the patch to find the via hole feed point. It provides a computer-readable recording medium.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art may easily implement the technical idea of the present invention. do. In the drawings, the same reference numerals are used for the same components as in the prior art.

FIG. 1 is a view showing the structure of a dual polarized microstrip antenna according to a first embodiment of the present invention, and FIGS. 2A and 2B are diagrams illustrating a feeding method in which a via hole and a microstrip line in FIG. 1 are mixed. . In the figure, A represents a first microstrip substrate, B represents a second microstrip substrate, 11 and 21 are radiating elements, 12 are microstrip line feed lines, 13 are via holes, 14 are via hole feeds, 22 is dielectric, 23 Silver ground plane, 24 is a power supply part, 25 is a proof, 26 is a relief hole, respectively.

The configuration of the dual polarized microstrip antenna according to the first embodiment of the present invention includes a first microstrip substrate A on which the radiating element 11 and the microstrip line 12 feeder are mounted, and a microstrip line. The second microstrip substrate B on which the configured via hole feed part 14 is mounted, and the via hole for coupling the radiating element 11 of the first microstrip substrate to the via hole feed part 14 of the second microstrip substrate. And a double feeding structure through the feed through the microstrip line and the via hole and its feed portion. In particular, in the above configuration, the microstrip line 12 and the via hole 13 are characterized in that they have a vertical structure.

That is, the dual polarized microstrip antenna of the present invention according to the first embodiment uses two microstrip substrates in order to be expandable to a two-dimensional (planar) array antenna, but has a first microstrip positioned on the top. The radiator and the microstrip line feeder are positioned in the substrate, and the second microstrip substrate positioned below the via is located in the via hole feeder formed of the microstrip line. The via holes are used as shown in FIGS. 2A and 2B. And a structure for joining the radiator on the first microstrip substrate and the via hole feed section on the second microstrip substrate. Therefore, if the above structure is expanded in plan, it becomes a small and lightweight two-dimensional array antenna that can obtain polarization diversity gain. In the above configuration, the via hole includes a probe 25 and a relief hole 26 as the probe element, as shown in FIGS. 2A and 2B.

As shown in FIG. 1, the width and length of the radiator have the same half-wave length (λg / 2) of the resonant frequency fr and are driven by a feed line using a mixture of a microstrip line and a via hole. do.

First, since the influence of the via hole is not large when feeding only the microstrip line lying on the x-axis, the antenna can be equalized as shown in FIG. 4, and the antenna operates at the resonance frequency fr. On the other hand, since the polarization of the rectangular microstrip patch antenna is the same as the feeding direction, it becomes a linear polarization toward the x-axis.

Next, since the influence of the microstrip line lying on the x-axis is not large when driving only the via hole feed part in FIG. 1, the antenna can be equalized as shown in FIG. 5, and the antenna operates at the same resonant frequency fr as described above. Since the via hole feed portion has a structure parallel to the y axis, it becomes a linear polarization toward the y axis.

Therefore, when this antenna is fed simultaneously in the x-axis and y-axis directions, both feed units operate at the resonant frequency fr, and in the case of polarization, linearly polarized toward the x-axis and two linearly directed to the y-axis as shown in FIG. It operates as a dual polarized antenna that can simultaneously obtain polarization.

3 illustrates the structure of a dual polarized microstrip antenna according to a second embodiment of the present invention.

The configuration of the dual polarized microstrip antenna of the present invention according to the second embodiment includes a first microstrip substrate A on which a feeder is mounted by the radiating element 31 and the microstrip line 32, and the microstrip. A slot 33 formed vertically with the line 32, and a second microstrip substrate B on which the slot-coupled feed line 34 is mounted, the feed through the microstrip line and the slot-coupled feed line It has a double feed structure through (34).

That is, the dual polarized microstrip antenna of the present invention according to the second embodiment uses two microstrip substrates so as to be expandable to a two-dimensional (planar) array antenna, and has a first microstrip positioned on the top. The radiator and the microstrip line feeder are positioned on the substrate, and the second microstrip substrate located below the slot is coupled to the slot-coupled feed portion formed by the microstrip line. As in the case of the first embodiment, the slot is used as the first embodiment. And a structure for joining the radiator on the microstrip substrate and the slot-coupled feed section on the second microstrip substrate. Therefore, if the above structure is expanded in plan, it becomes a small and lightweight two-dimensional array antenna that can obtain polarization diversity gain.

Now, a design method of a dual polarized microstrip antenna according to the present invention will be described.

7 is a flowchart showing a design procedure for obtaining the size of the radiator (radiating element) of the present invention.

As shown in the figure, the width (W) and the length (L) of the antenna is initialized to half wavelength, and the frequency, loss tangent, permittivity, metal thickness, and dielectric height are respectively input (710). ).

Then, in the first loop, the input impedance of the microstrip antenna is calculated using the input values for the microstrip line feeder, and then the L value is increased if the imaginary part is negative, and L if the imaginary part is positive. Decreases the value, and obtains the antenna length 'L' whose imaginary part becomes '0' (721). In the next loop, the 'L' value is made wide by using the input value for the feed part mixed with the via hole and the microstrip line. (Semi-wavelength value) is the length of the microstrip by increasing the W value if the imaginary part of the antenna's input impedance is negative, and decreasing the W value if the imaginary part is positive. The length W 'of the antenna is obtained (723). In the final loop 725, the width of the feed part of the microstrip line is W 'and the length of L' is substituted, so that when the imaginary part of the antenna's input impedance becomes '0', it exits the loop and obtains a result value. If it is not 0 ', the process starts repeatedly from the first loop 721 until it satisfies the condition (720). As a result, the width and length of the resultant antenna have the same resonant frequency, thereby obtaining the same value (730). Next, in order to find the via hole feed point, the feed point xf is gradually changed from the edge of the patch to obtain a feed point xf having the same input impedance as that of the via hole (740).

As described above, the algorithm of the present invention can be used to design a dual polarized dual resonant microstrip antenna of dual feed structure for both satellite communication transmission and reception, which can replace the existing parabolic antenna. That is, first, the width and length of the microstrip antenna are initialized to half-wavelength values of 14.25 GHz (microstrip feed section) and 12.50 GHz (feed section mixed with via hole and microstrip line), and then the first loop door (microstrip line) Calculate the input impedance of the microstrip antenna when the resonant frequency is 14.25 GHz using this value in the feeder section, and increase the L value if the imaginary part is negative, and decrease the L value if the imaginary part is positive. In the next loop (feeding part mixed with via hole and microstrip line), L 'value is width and W (half-wavelength value) is the length. With a resonance frequency of 12.50 GHz, the imaginary part of the antenna's input impedance increases the W value if negative, and the imaginary part decreases the W value and the imaginary part becomes '0'. The trip antenna is rescued the length W '. Again, in the last loop (microstrip line feeder), the resonance frequency is 14.25 GHz, and the width is W 'and L' are substituted for the imaginary part of the antenna's input impedance. If it is not '0', it starts again from the beginning and repeats until the condition is satisfied, and the size of the dual resonant antenna operating at 14.25 GHz and 12.50 GHz can be obtained. In addition, since the transmission and reception polarization is different from each other, such as satellite communication, it can be seen that it is very suitable for the transmission and reception antenna.

A microstrip line having a characteristic impedance of 50 를 is matched to one side of the antenna by using a λg / 4 converter. The feeder that mixes the via hole and the microstrip line is located on the microstrip antenna where the via hole is located at the input impedance equal to the characteristic impedance of the via hole and connected to each other as shown in FIG. At this time, the probe and the relief hole constituting the via hole are determined from the following equation.

Hereinafter, a method of extending the dual polarized antenna of the dual feed structure to the two-dimensional array antenna.

As described above, the feed portion of the microstrip line feeder, the feed portion mixed with the via hole and the microstrip line are located on each of the two substrates and are coupled to the via holes. That is, in the case of the microstrip line, the microstrip line having a size of 50 Ω in the front while the arrangement is λg / 4 while the microstrip line is 50 앞에서 in the front so as to have a small size to prevent the coupling between the feeder and the reflector when expanding into the array. The converter was coupled to each radiating element, and T-junction was used to inject uniform power into each radiating element. However, the connector attaches 50 붙 to receive RF signal. The feed section, which is a combination of the via hole and the microstrip line located on the lower substrate, is directly matched to the via hole having the 50 Ω microstrip line and the characteristic impedance of 50 와 as in the case of the single antenna. The mating with the microstrip line was extended using T-matching as with the microstrip line feed. This structure has a very compact planar structure because the upper substrate and the lower substrate are bonded to each other, so it is very easy to install in an indoor wall.

As described above, the design method of the compact and lightweight dual polarized antenna using the mixed feed method can be effectively used for the indoor base station for IMT-2000 and the dual polarized dual resonant antenna for satellite communication transmission and reception.

Although the foregoing has been described with respect to embodiments of the present invention, those skilled in the art will understand that various implementations are possible within the scope of the technical idea of the present invention.

As described above, the present invention has proposed a dual feeding structure that can be extended to a two-dimensional array by solving a problem of expanding a two-dimensional array, which was a problem of the conventional double feeding method, and the proposed algorithm can simply design a dual polarized antenna. In addition, a small transmit / receive antenna that can replace a small transmit / receive antenna that can replace a conventional parabolic antenna in satellite communication can be designed. In addition, this design method has a very elegant effect that can easily produce a smaller thin antenna as a transmission antenna for indoor use.

Claims (11)

In a dual polarized microstrip antenna, A first microstrip substrate for mounting a first feeding part composed of a radiating element and a microstrip line; A second microstrip substrate for mounting a second feed section formed of a microstrip line; Means for coupling a radiating element on said first microstrip substrate and a second feeder on said second microstrip substrate, The dual polarization microstrip antenna of claim 1, wherein the first microstrip substrate is positioned at the top and the second microstrip substrate is positioned at the bottom. The method of claim 1, Means for coupling the radiating element and the second feeder, The dual polarization microstrip antenna of the dual feed structure, characterized in that the via-hole perpendicular to the first feed portion. The method of claim 1, The means for combining, And a probe as a probe element and a relief hole of said probe portion. The method of claim 1, And the dual feed structure is configured to match the microstrip line with the radiating element by using a λg / 4 converter to prevent coupling due to the expansion of the two-dimensional array. The method of claim 4, wherein A dual polarization microstrip antenna having a T-match to supply uniform power to the radiating element. The method of claim 5, When the microstrip line and the via hole is matched, the T-match is achieved, but the dual polarization microstrip antenna of the dual feed structure, characterized in that it extends in the same way as the microstrip line. The method of claim 1, Means for coupling the radiating element and the second feeder, The dual polarization microstrip antenna of the dual feed structure, characterized in that the slot having a predetermined shape perpendicular to the first feed portion. In the design method of a dual polarized microstrip antenna, A first step of initializing the width and the length of the antenna to half wavelength values; A second step of calculating the input impedance of the microstrip antenna using the transmission line model and changing the length and width of the antenna such that the imaginary part of the input impedance becomes '0' while calculating the input impedance of the antenna at the resonance frequency; A third step of outputting a width and a length of the antenna obtained through the second step; And Step 4 to find the feed point (xf) which has the same input impedance as the characteristic impedance of the via hole, while gradually changing the starting feed point (xf) from the edge of the patch to find the via hole feed point. Design method of a dual polarized microstrip antenna comprising a. The method of claim 8, The second step, Calculate the input impedance of the microstrip antenna using the inputs to the microstrip line feeder, but increase the L value if the imaginary part is negative and reduce the L value if the imaginary part is positive, A fifth step of obtaining an antenna length 'L' which is an additional '0'; Calculate the width of 'L' and the width of W (half-wavelength) by using the input values for the feed section mixed with via hole and microstrip line, but increase the W value if the imaginary part of the antenna's input impedance is negative A sixth step of reducing the W value when the imaginary part is positive and repeating the calculation to obtain the length W 'of the microstrip antenna whose imaginary part becomes' 0'; And Calculating the width of the feed section of the microstrip line by W 'and substituting L' for the length, and repeating operation from the fifth step until the imaginary part of the input impedance of the antenna becomes '0'. Dual polarized microstrip antenna design method comprising a. In a dual polarized microstrip antenna design system with a microprocessor, A first function of initializing a width and a length of the antenna to half wavelength values; A second function of calculating an input impedance of the microstrip antenna using a transmission line model and changing the length and width of the antenna such that the imaginary part of the input impedance becomes '0' while calculating the input impedance of the antenna at the resonance frequency; A third function of outputting a width and a length of the antenna obtained through the second function; And A fourth function of finding a feed point (xf) having the same input impedance as the characteristic impedance of the via hole, while gradually changing the starting feed point (xf) from the edge of the patch to find the via hole feed point; A computer-readable recording medium containing a program for realizing the problem. The method of claim 10, The second function, Calculate the input impedance of the microstrip antenna using the inputs to the microstrip line feeder, but increase the L value if the imaginary part is negative and reduce the L value if the imaginary part is positive, A fifth function of obtaining an antenna length 'L' which becomes an additional '0'; Calculate the width of 'L' and the width of W (half-wavelength) by using the input values for the feed section mixed with via hole and microstrip line, but increase the W value if the imaginary part of the antenna's input impedance is negative A sixth function of reducing the W value when the imaginary part is positive and repeating the calculation to obtain the length W 'of the microstrip antenna whose imaginary part becomes' 0'; And The seventh function of calculating the width by feeding the width of the feed portion of the microstrip line to W 'and substituting L' for the length, repeating from the fifth step until the imaginary part of the input impedance of the antenna becomes '0'. Computer-readable recording medium containing a program, characterized in that it comprises a.