KR102000121B1 - Microstrip patch array antenna - Google Patents

Abstract

Disclosed is a microstrip patch array antenna. According to one embodiment of the present invention, the microstrip patch array antenna comprises: a substrate; a radiation unit formed on an upper surface of the substrate and including a plurality of radiating element rows including a plurality of radiating elements arranged in a first direction, arranged in a second direction; a power supply network formed on an upper surface of the substrate, including up and down, left and right symmetry around a power supply unit for supplying electric power, and including a transmission line for transmitting electric power from the power supply unit to each radiating element; and a ground unit formed on the lower surface of the substrate. The power supply network may be applied with a parallel feeding method and a serial feeding method.

Description

[0001] MICROSTRIP PATCH ARRAY ANTENNA [0002]

The present invention relates to a microstrip patch array antenna, and more particularly, to a microstrip patch array antenna designed to have a low side-leaf size using a parallel-to-serial feed network having different power distribution ratios.

The microstrip patch array antenna can be used for various purposes because it can obtain high gain with small size and low cost, and the feeding method can be roughly classified into parallel feeding and serial feeding. The parallel feed structure has the advantage of having a wide impedance bandwidth, but since the length of the line becomes long, it is difficult to obtain high gain due to the loss occurring in the line in the high frequency band.

There is also a limit to reducing the size of side lobes due to unwanted radiation from the track. In order to reduce the size of the side lobes in both the xz-plane and the yz-plane, the power supplied to each radiation element must be different, and it is difficult to use the parallel power supply structure because the structure becomes complicated to make the power distribution ratio different. Although the series feed structure has a small loss due to a short length of the line, there is a disadvantage in that it is difficult to realize a desired power division ratio due to the limitation of the line width when connecting multiple radiation elements, and there is a problem in manufacturing a two-dimensional array antenna.

Therefore, it is required to develop a technology for a microstrip patch array antenna having advantages of a parallel feed structure and a serial feed structure and having a high gain and a low side leaf size.

In this connection, Korean Patent Laid-Open No. 10-2009-0046590, entitled " Microstrip Patch Type Antenna ", exists.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a microstrip patch array antenna having a high gain and a low side leaf size.

The technical problems of the present invention are not limited to the above-mentioned technical problems, and other technical problems which are not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided a microstrip patch array antenna comprising: a substrate; a plurality of radiating element columns formed on a top surface of the substrate and including a plurality of radiating elements arranged in a first direction; And a transmission line formed on the upper surface of the substrate and symmetric with respect to the feeding part for feeding power and transmitting power from the feeding part to each radiating element, A feeder network, and a grounding unit formed on a bottom surface of the substrate, wherein the feed network may be a parallel feed system or a serial feed system.

Preferably, the radiating part may be configured in an array form of N X M (N, M is a natural number) radiating elements.

Preferably, the radiating element is a microstrip patch, and the width and length of the microstrip patch are 9 mm.

Preferably, the feeding network has a center frequency of 10.5 GHz, and the electrical length of the line connecting the radiating elements may be the antenna operating frequency wavelength (?).

Preferably, the transmission line of the feed network is provided with a plurality of? / 4 impedance converters, and the voltage division ratio can be adjusted by adjusting the characteristic impedance value of the? / 4 impedance converter.

Preferably, the feed network comprises first and second series feed lines with at least one < RTI ID = 0.0 > l / 4 < / RTI > impedance transducer and symmetrical to each other, And a parallel feed line portion connected to the feed line.

Preferably, the bandwidth can be extended by adjusting the length of the transmission line connected to the feeder in the feed network or by changing the linewidth of the transmission line connected to each radiating element.

Preferably, in the feed network, a meander line is added on both sides of the feeder as a reference, so that the length of the transmission line can be adjusted.

According to another aspect of the present invention, there is provided a microstrip patch array antenna comprising: a first substrate; a plurality of radiating elements formed on a top surface of the first substrate, the plurality of radiating elements being arranged in a first direction; A ground plane in which a plurality of slots are formed so as to face a position of a radiating element of the radiating section; a second substrate on which the ground plane is formed on an upper surface; And a feed line formed on the lower surface of the substrate and symmetrical in the up, down, left, and right directions around the feed part for feeding power, and a transmission line for transmitting the power from the feed part to each radiating element, The feed method and the serial feed method can be applied.

Preferably, the transmission line of the feed network is provided with a plurality of? / 4 impedance converters, and the voltage division ratio can be adjusted by adjusting the characteristic impedance value of the? / 4 impedance converter.

Preferably, the feed network comprises first and second series feed lines with at least one < RTI ID = 0.0 > l / 4 < / RTI > impedance transducer and symmetrical to each other, And a parallel feed line portion connected to the feed line.

Preferably, the bandwidth can be extended by adjusting the length of the transmission line connected to the feeder in the feed network or by changing the linewidth of the transmission line connected to each radiating element.

According to the present invention, an array antenna having a high gain and a low side-leaf size can be designed by adjusting power supplied to each patch antenna using a parallel-to-serial feeding structure combining a plurality of quarter-wave impedance converters.

In addition, the characteristic impedance of the 1/4 wavelength impedance converter can be adjusted to have a desired power distribution ratio, and the loss is less than that of the parallel feed structure, and it is easier to manufacture than the serial feed structure.

In addition, it has all the advantages of parallel feed structure and serial feed structure, and can achieve a desired power share ratio compared with a parallel feed structure. As compared with a serial feed structure in which power is distributed in only one direction, power is distributed in both directions The ratio of the power supplied to each patch antenna can be adjusted as desired.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood to those of ordinary skill in the art from the following description.

1 is a side view of a microstrip patch array antenna according to an embodiment of the present invention.
2 is a front view of a microstrip patch array antenna according to an embodiment of the present invention.
3 is a view for explaining a power supply network according to an embodiment of the present invention.
4 is a view for explaining a feeding structure of an array antenna according to an embodiment of the present invention.
5 is a view for explaining a serial feed line section and a parallel feed line section according to an embodiment of the present invention.
FIG. 6 is a diagram for explaining the feed network of FIG. 3 using a serial feed line unit and a parallel feed line unit.
7 is a diagram for explaining a method of adjusting a length of a transmission line of a feed network to extend a bandwidth according to an embodiment of the present invention.
8 is a diagram for explaining a method of adjusting a line width of a transmission line of a feed network in order to expand a bandwidth according to an embodiment of the present invention.
9 is a diagram for explaining a case in which a meander line is added to a feed network to extend a bandwidth according to an embodiment of the present invention.
10 is a graph comparing radiation patterns of a 4 x 4 array antenna according to a variation of a power distribution ratio at 10.5 GHz according to an embodiment of the present invention.
11 is a view showing a radiation pattern of a 4x4 array antenna according to a variation of the interval D of patch antennas at 10.5 GHz according to an embodiment of the present invention.
12 is a graph of the reflection coefficient of an array antenna simulated at an antenna spacing D = 20 mm according to an embodiment of the present invention.
FIG. 13 shows a radiation pattern in the case of adjusting the length of a transmission line in a feed network as shown in FIG.
14 is a graph showing the reflection coefficient when the length of the transmission line is adjusted in the feed network as shown in FIG.
15 is a graph showing the reflection coefficient of the array antenna optimized when the length of the transmission line is 7 mm according to an embodiment of the present invention.
16 is a graph showing a radiation pattern of an array antenna optimized for a transmission line length of 7 mm according to an embodiment of the present invention.
17 is a graph showing a radiation pattern when the line width of the transmission line in the feed network is changed from 0.2 mm to 0.3 mm as shown in FIG.
18 is a graph showing the reflection coefficient when the line width of the transmission line in the feed network is changed from 0.2 mm to 0.3 mm as shown in FIG.
FIG. 19 is a graph showing the radiation patterns of the array antenna when the power distribution ratios are 1: 3: 3: 1 and 1: 5: 5: 1 by changing the line width of the transmission line from 0.2 mm to 0.3 mm in the feed network as shown in FIG. FIG.
FIG. 20 is a graph showing the reflection coefficient when the meander line is added in the feed network as shown in FIG.
FIG. 21 is a graph comparing reflection coefficients when a meander line is added and when it is not added according to an embodiment of the present invention.
FIG. 22 is a graph comparing radiation patterns when a meander line is added and when radiation is not added according to an embodiment of the present invention.
23 is a side view for explaining a microstrip patch array antenna according to another embodiment of the present invention.
24 is a cross-sectional view of a microstrip patch antenna according to another embodiment of the present invention.
25 is a graph showing reflection coefficients of a microstrip patch array antenna according to another embodiment of the present invention.
26 is a graph showing a radiation pattern of a microstrip patch array antenna according to another 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. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the 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 elements, but the elements 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 a second component, and similarly, the second component may also be referred to as a first component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations 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 to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

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

FIG. 1 is a side view of a microstrip patch array antenna according to an embodiment of the present invention, FIG. 2 is a front view of a microstrip patch array antenna according to an embodiment of the present invention, and FIG. FIG. 4 is a view for explaining a power feeding structure of an array antenna according to an embodiment of the present invention, and FIG. 5 is a view for explaining a power feeding network according to an embodiment of the present invention. FIG. 6 is a diagram for explaining the feed network of FIG. 3 using a serial feed line unit and a parallel feed line unit, and FIG. 7 is a diagram for explaining a feed line of the feed network in order to expand a bandwidth according to an embodiment of the present invention. FIG. 8 is a view for explaining a method of adjusting a length of a transmission line of a feed network in order to extend a bandwidth according to an embodiment of the present invention. FIG. 9 is a diagram for explaining a case where a meander line is added to a feed network to extend a bandwidth according to an embodiment of the present invention.

1 and 2, the microstrip patch array antenna 100 includes a substrate 110, a radiation part 125, a feeding part 130, a feeding network 140, and a grounding part 150.

)는 2.2, 손실 탄젠트(tan

)는 0.0019, 두께(h)는 0.7874 mm로 구성될 수 있다.A ground portion (ground plane) 150 may be formed on the bottom surface of the substrate 110. At this time, the substrate 110 may be composed of a Rogers RT / duroid 5880 product. Also, the dielectric constant (< RTI ID = 0.0 >

) Is 2.2, loss tangent (tan

) Is 0.0019, and the thickness ( h) is 0.7874 mm.

The radiating part 125 is formed on the upper surface of the substrate 110 and a plurality of radiating element rows including a plurality of radiating elements 120 arranged in the first direction are arranged in the second direction. That is, the radiating part 125 includes a plurality of radiating element rows arranged in the horizontal direction (X axis direction), and each of the plurality of radiating element columns is connected in series in the vertical direction (Y axis direction).

The radiation unit 125 may be configured as an array of N X M (N, M is a natural number), and N and M may be the same number or different numbers. For example, the radiating portion may be configured in various arrangements such as 4 X 4, 6 X 6, 8 X 8, 4 X 8, and 4 X 6.

Hereinafter, for convenience of explanation, a case where the radiation unit 125 is configured as a 4 X 4 array as shown in FIG. 2 will be described. In this case, it includes 16 (4 x 4) radiating elements 120 mounted on the substrate 110. That is, the radiating section 125 includes four radiating element rows, and each radiating element row includes four radiating elements 120. [ The radiating element 120 has a constant width Wp and length, and the radiating elements 120 have a constant spacing D therebetween.

The radiating element 120 may be a radiating element in the form of a microstrip patch. That is, the radiating element 120 may be a radiating element in the form of a microstrip patch having a length of a half wavelength (?) With respect to a center frequency. At this time, the width and length of the microstrip patch may be 9 mm. In addition, the radiating element 120 may be a square patch, a circular patch, a rectangular patch, or any other kind of patch with slots. By arranging the microstrip patches in the form of 4 x 4, an array antenna can be constructed.

The power feeder 130 is configured to transmit power to be provided to the radiation unit through the power feed network, and may be located at the center of the power feed network 140 as shown in FIG. In one embodiment of the present invention, the feeding part 130 may be changed into various feeding forms such as a coaxial line or a coplanar waveguide (CPW) using a transition structure.

The feeding network 140 is formed on the upper surface of the substrate 110 and symmetrically arranged vertically and horizontally with respect to the feeding part 130 that feeds power to transmit power from the feeding part 130 to the radiating elements 120 And a transmission line. At this time, the center frequency of each radiating element 120 and the feeding network 140 may be 10.5 GHz, and the electrical length of the line connecting each radiating element 120 may be?. The line can be bent in some sections to adjust the length of the line so that the electrical length of the line connecting each node is? Regardless of the antenna interval. Since the feed network 140 has a symmetrical structure with respect to the feeder 130, it can be powered by connecting a coaxial line to the center of the entire feeder line.

The power supply network 140 has a structure in which a serial power supply structure and a parallel power supply structure are combined as shown in FIG. 3, and the power supply network 140 is symmetrical about the power supply portion. In this case, the parallel feed structure may be the same as shown in FIG. 4 (a), the series feed structure may be the same as (b), and the length and thickness of the transmission line (feed line) may be different for adjusting the characteristic impedance value have. Further, in the transmission line of the feed network 140, a λ / 4 impedance converter (λ / 4) of the operating frequency wavelength λ of the antenna is arranged so that each output port has a desired level of power distribution ratio And the voltage division ratio can be adjusted by adjusting the characteristic impedance value of the? / 4 impedance converter. For example, in the case of a 4 x 4 arrangement, two λ / 4 impedance converters are provided between the output ports to which the radiating elements are connected, and the characteristic impedance values of the λ / 4 impedance converters are adjusted to adjust the power division ratio Can be adjusted. For example, it is possible to control the power division ratio of each output port by adjusting the characteristic impedance value of the? / 4 impedance converter to 1: 1: 1: 1, 1: 3: 3: 1, 1: 5: 5:

Hereinafter, the power supply network 140 having a 4X4 array will be described in detail. The feeding network 140 may have a structure in which a series feed line portion and a parallel feed line are additionally coupled to each other and a plurality of parallel feed line portions such as shown in FIG. 5 (a) and a parallel feed line portion such as FIG. . In this case, the parallel feeder line portion may have a structure in which two serial feeder portions and a lambda / 4 impedance converter are connected in parallel. The two serial feed line portions, that is, the first and second serial feeder portions may be lines connecting the radiating element rows, and when the radiating element array is composed of four radiating elements, between the output ports connecting the radiating elements Two? / 4 impedance converters are provided. In addition, since the feed network 140 is symmetrical in the up, down, left, and right directions, the first and second serial feed lines should be symmetrical. 5, the first to third? / 4 impedance converters are provided, and the second serial feeder portion may be symmetrical with respect to the first serial feeder portion with respect to a, have. For example, if the power distribution ratio is 1: 5: 5: 1 and the power distribution ratio is 1: 5: 5: 1, the power division ratio between Ports 2 and 3 in the first serial feeder line portion may be 5: 1. That is, 5 * z _in1 = z _in2 .

As shown in FIG. 5 (b), the parallel feed line may be formed by connecting the first serial feed line section, the second serial feed line section, and the fourth λ / 4 impedance transducer line in parallel. Accordingly, the feed network 140 shown in FIG. 3 may include a structure in which two parallel feed parts 1 and four series feed parts 1 are combined as shown in FIG. have.

Since the feed network 140 is symmetrical on both sides with respect to the feeder 130, the seventh lambda / 4 impedance converter is provided in the transmission line connected to the feeder 130, and the seventh lambda / 4 and the fourth serial feeder line portion, the third and fourth serial feeder portions are connected in parallel with the sixth? / 4 impedance converter, the sixth? / 4 impedance converter is connected in parallel with the fifth? / 4 impedance converter, And a fifth? / 4 impedance converter is connected to the first parallel feed line portion. Since both sides of the feeding network 140 are symmetrical with respect to the feeding part 130, the A area and the B area may be symmetrical with respect to the feeding part 130.

For example, if the power distribution ratio is 1: 5: 5: 1 and the power distribution ratio is 4: 4, the power distribution ratio between the parallel feeder line and the first and second serial feeder lines may be 1: 5. That is, 5 * (z _in5 ) / 2 = z _in6 Lt; / RTI >

The feed network 140 may include a plurality of transmission lines having different electrical lengths and characteristic impedances to provide impedance matching between the radiating element 120 and the input port. Also, the feeding network 140 can design an antenna having a low side-leaf size and a high gain by adjusting the lengths of the transmission lines on both sides with respect to the feeder 130 as shown in FIG. 7A. In addition, in the feeding network 140, by changing the line width as shown in FIG. 8B, an antenna having a low side-leaf size and a high gain can be designed.

As described above, the power feeding network 140 can impedance match the impedance of the radiation unit 120 with respect to the feeding unit 130. [ That is, the characteristic impedance value of the? / 4 impedance converter can be adjusted in the feed network 140 to obtain a desired power distribution ratio. The characteristic impedances of each? / 4 impedance converter to obtain the respective power distribution ratios can be as shown in Table 1 below.

[Table 1]

The microstrip patch array antenna 100 according to the present invention may be a microstrip patch array antenna designed to have a high gain and a low side leaf size using the parallel-to-serial feed network 140 having different power distribution ratios. At this time, the power distribution ratio can be adjusted by connecting several 1/4 wavelength impedance converters and adjusting the characteristic impedance value of each 1/4 wavelength impedance converter.

The microstrip patch array antenna 100 having such a structure has high gain and low side lobe size, but has a disadvantage in that the bandwidth is not wide. In order to increase the bandwidth, it is possible to design the feed network 140 in which a meander line 170 is added on both sides of the feeder 130 as shown in FIG. By adding the meander line 170, the length of the transmission line can be increased, thereby widening the bandwidth. At this time, the meander line 170 may be bent like A

x 3.5

x 0.028

)인 경우, 시뮬레이션 및 최적화를 수행한 결과에 대해 설명하기로 한다. 이때, Wq _p = 0.3 mm, W ₁ = 0.7 mm, W ₂ = 0.7 mm, Wq ₁ = 0.8 mm, Wq ₂ = 0.5 mm, Wq ₃ = 2.4 mm, Wq ₄ = 1.4 mm, Wq ₅ = 1.2 mm, Wq ₆ = 0.5 mm, Wq ₇ = 2 mm, W _i = 0.3 mm, Lq _p = 4.5 mm, L ₁ = 4.6 mm, Lq ₁ = 5.3 mm, Lq ₂ = 5.4mm, Lq ₃ = 5.4 mm, Lq ₄ = 5.5 mm, Lq ₅ = 5.5 mm, Lq ₆ = 5.4 mm, Lq ₇ = 7 mm, dp ₁ = 1.7 mm, dp ₂ = 1.7 mm, W = 100 mm, W _p = 9 mm, D = 20 mm, h = 0.7874 mm로 설정할 수 있다. Hereinafter, the width and the length Wp of the microstrip patch array antenna 100 are 9 mm, and the sizes of the array antennas 100 mm x 100 mm x 0.7874 mm (3.5

x 3.5

x 0.028

), The results of simulation and optimization will be described. In this case, Wq _p = 0.3 mm, W ₁ = 0.7 mm, W ₂ = 0.7 mm, Wq ₁ = 0.8 mm, Wq ₂ = 0.5 mm, Wq ₃ = 2.4 mm, Wq ₄ = 1.4 mm, Wq ₅ = Lq ₁ = 5.3 mm, Lq ₂ = 5.4 mm, Lq ₃ = 5.4 mm, Lq ₄ = 5 mm, Wq ₆ = 0.5 mm, Wq ₇ = 2 mm, W _i = 0.3 mm, Lq _p = 4.5 mm, L ₁ = _{= 5.5 mm, Lq 5 = 5.5} mm, Lq 6 = 5.4 mm, Lq 7 = 7 mm, dp 1 = 1.7 mm, dp 2 = 1.7 mm, W = 100 mm, W p = 9 mm, D = 20 mm, h = 0.7874 mm.

10 is a graph comparing radiation patterns of a 4x4 array antenna according to a variation of a power distribution ratio at 10.5 GHz according to an embodiment of the present invention. 10 shows a result of comparison of radiation patterns of the array antennas when the power distribution ratio is 1: 1: 1: 1, 1: 3: 3: (B) is a radiation pattern in the yz-plane.

Table 2 shows the gain and the size of the side lobes of the array antennas having the respective power distribution ratios.

[Table 2]

It can be seen that the size of the side lobes of the array antenna is the highest when the power distribution ratio is 1: 1: 1: 1, and the size of the side lobes decreases as the power distribution ratio increases.

FIG. 11 is a diagram illustrating a radiation pattern of a 4 × 4 array antenna according to a variation of the interval D of patch antennas at 10.5 GHz according to an embodiment of the present invention. In this case, the array antenna has a power distribution ratio of 1: 5: 5: 1, and the radiation pattern of the array antenna according to the distance D between the center and the center of each microstrip patch antenna is shown by (a) Represents the radiation pattern of the yz-plane.

Referring to FIG. 11, as the spacing D of the patch antenna decreases, the size of the side lobes of the xz-plane decreases, but the gain of the antenna decreases. In case of yz-plane, the size of side leaf is smallest when D is 20mm.

The gain and side size of the array antenna at 10.5 GHz according to the spacing ( D) between the patch antennas can be as shown in Table 3 below.

[Table 3]

at 10.5 GHz)임을 알 수 있다.Referring to Table 3, the interval where the side lobe size is less than -25 dB and the gain is more than 18 dBi is D = 20 mm (~ 0.7

at 10.5 GHz).

12 is a graph of the reflection coefficient of an array antenna simulated at an antenna spacing D = 20 mm according to an embodiment of the present invention.

Referring to FIG. 12, the reflection coefficient is -19.8 dB at a center frequency of 10.5 GHz, and the bandwidth of less than -10 dB is 220 MHz, and the bandwidth ratio is 2.1%. The size of the side lobes is -28.0 dB and -26.5 dB for the xz-plane and the yz-plane, respectively, and the gain is 18.2 dBi.

x 3.5

x 0.028

)일 수 있다. In conclusion, we can design a 4 x 4 microstrip patch array antenna with high gain and low sidelobe size using multiple 1/4 wavelength impedance transducers in a parallel-to-serial feed structure. This structure can control the characteristic impedance value of each 1/4 wavelength impedance converter to have a desired power distribution ratio, and has a merit that the loss is less than that of the parallel feeding structure and the manufacturing is easier than the serial feeding structure. As a result of the optimization of the microstrip array antenna shown in FIG. 1, the gain of the array antenna was 18.2 dBi at 10.5 GHz, and the side leaf size was -28.0 dB in the xz-plane and -26.5 dB in the yz- . Also, | S ₁₁ | The specific bandwidth of <-10 dB is 2.1% and the size of the array antenna is 100 mm x 100 mm x 0.7874 mm (3.5

x 3.5

x 0.028

).

FIG. 13 shows a radiation pattern in the case of adjusting the length of a transmission line in a feed network as shown in FIG. FIG. 13 is a graph comparing the radiation patterns when the lengths of the transmission lines are 4.2 mm, 5.2 mm, and 6.2 mm, wherein (a) shows the xz-plane and (b) shows the radiation pattern of the yz-plane. When the transmission line length is 6.2 mm, the side lobes are -27.8 dB and -25.2 dB in the xz-plane and yz-plane, respectively, and the gain is 18.3 dBi.

14 is a graph showing the reflection coefficient when the length of the transmission line is adjusted in the feed network as shown in FIG. 14 is a graph comparing reflection coefficients when the lengths of the transmission lines are 4.2 mm, 5.2 mm, and 6.2 mm. When the transmission line length is 6.2 mm, the reflection coefficient is -12 dB at the center frequency of 10.5 GHz, and the bandwidth less than -10 dB is 201 MHz and the bandwidth is 1.9%.

15 is a graph showing the reflection coefficient of the array antenna optimized when the length of the transmission line is 7 mm according to an embodiment of the present invention.

Referring to FIG. 15, the reflection coefficient is -20.8 dB at a center frequency of 10.5 GHz, and the bandwidth of less than -10 dB is 230 MHz, and the bandwidth is 2.2%.

16 is a graph showing a radiation pattern of an array antenna optimized for a transmission line length of 7 mm according to an embodiment of the present invention.

Referring to FIG. 16, when the transmission line length is 7 mm, the side lobe size is -26.9 dB, -26.9 dB, and the gain is 18.3 dBi in the xz-plane and the yz-plane, respectively.

17 is a graph showing a radiation pattern when the line width of the transmission line in the feed network is changed from 0.2 mm to 0.3 mm as shown in FIG. 17, it can be seen that the side lobe size is -28.0 dB and -26.5 dB in the xz-plane and the yz-plane, respectively, and the gain is 18.2 dBi.

18 is a graph showing the reflection coefficient when the line width of the transmission line in the feed network is changed from 0.2 mm to 0.3 mm as shown in FIG. Referring to FIG. 18, it can be seen that the reflection coefficient is -19.7 dB at a center frequency of 10.5 GHz, and the bandwidth of less than -10 dB is 220 MHz, and the bandwidth width is 2.1%.

FIG. 19 is a graph showing the radiation patterns of the array antenna when the power distribution ratios are 1: 3: 3: 1 and 1: 5: 5: 1 by changing the line width of the transmission line from 0.2 mm to 0.3 mm in the feed network as shown in FIG. FIG. (a) is a radiation pattern in the xz-plane, and (b) is a radiation pattern in the yz-plane.

19, when the power distribution ratio is 1: 3: 3: 1, the side lobe size is -21.0 dB and -21.6 dB in the xz-plane and the yz-plane, respectively, and the gain is 18.8 dBi. Also, when the power distribution ratio is 1: 5: 5: 1, the side lobe size is -27.0 dB and -26.5 dB for the xz-plane and the yz-plane, respectively, and the gain is 18.2 dBi.

FIG. 20 is a graph showing the reflection coefficient when the meander line is added in the feed network as shown in FIG. (a) is the reflection coefficient when wm is 0.4 mm, 0.6 mm and 0.8 mm, (b) is the reflection coefficient when dm is 0.1 mm, 0.2 mm and 0.3 mm, (D) is the reflection coefficient when wqp is 0.2 mm, 0.3 mm, and 0.4 mm, and (e) is the reflection coefficient when lqp is 3 mm, 4 mm, and 4.5 mm, .

Referring to FIG. 20, when the wm is 0.6 mm or more and the dm is 0.1 mm or more, the bandwidth increase rate is high. Also, when lmi is 0.4 mm, it can be seen that the specific bandwidth which is less than -10 dB is 5.7%.

FIG. 21 is a graph comparing reflection coefficients when a meander line is added and when it is not added according to an embodiment of the present invention. Referring to FIG. 21, it can be seen that when the meander line is not added, the specific bandwidth which is less than -10 dB is 2.1%, while when the meander line is added, the specific bandwidth which is less than -10 dB is 5.5% .

FIG. 22 is a graph comparing radiation patterns when a meander line is added and when radiation is not added according to an embodiment of the present invention. Referring to FIG. 22, it can be seen that the gain is 18.2 dBi when the meander line is not added, and the gain is 16.9 dBi when the meander line is added. In addition, it can be seen that the side lobe size when the meander line is not added is -28.0 in the xz plane and -26.5 dB in the yz plane. In addition, it can be seen that the size of the side leaf added with the meander line is -28.6 in the xz plane and -20.7 dB in the yz plane.

FIG. 23 is a side view for explaining a microstrip patch array antenna according to another embodiment of the present invention, and FIG. 24 is a cross-sectional view of a microstrip patch antenna according to another embodiment of the present invention.

23, a microstrip patch array antenna 2300 according to another embodiment of the present invention includes a first substrate 2310, a radiation part 2320 formed on the upper surface of the first substrate 2310, a radiation part 2320 A second substrate 2330 having a ground plane 2360 formed on an upper surface thereof, a feed network 2350 formed on the lower surface of the second substrate 2330, And an air gap hg is present between the first substrate 2310 and the second substrate 2330. In this case,

The first substrate 2310 is electrically connected to the ground plane 2360, and the radiation part 2320 is formed on the upper surface. The antenna includes, but is not limited to, 16 (4 x 4) radiating elements mounted on top of the first substrate 2310.

The first substrate 2310, the radiation unit 2320, the power supply network 2350, and the power supply unit 2340 are the same as those in FIG. 1, and thus description thereof will be omitted.

The ground plane 2360 is formed so as to correspond to the position where the radiating elements are formed such that slots 2370 for opening coupling power supply are provided and slots 2370 are connected to NXN (N = 4) radiating elements .

A ground plane 2360 having a plurality of slots 2370 is formed on the upper surface of the second substrate 2330 and a feed network 2350 is formed on the lower surface of the second substrate 2330.

Accordingly, the power supplied to the power feeder 2340 is transmitted to each slot 2370 through the power feed network 2350, so that the radiating elements of the radiator 2320 operate.

25 is a graph showing reflection coefficients of a microstrip patch array antenna according to another embodiment of the present invention. Referring to FIG. 25, the reflection coefficient is -11.5 dB at a center frequency of 10.5 GHz, and the non-bandwidth width of the section of less than -10 dB is 17.2%.

26 is a graph showing a radiation pattern of a microstrip patch array antenna according to another embodiment of the present invention. Referring to FIG. 26, it can be seen that the side lobe size is -26.9 dB, -26.9 dB, and the gain is 18.3 dBi in the xz-plane and the yz-plane, respectively.

The microstrip patch array antenna configured as described above can have high gain and low side lobe size by adjusting power supplied to each patch antenna by using a parallel-to-serial feeding structure combining a plurality of quarter-wave impedance converters have. In addition, the characteristic impedance of the 1/4 wavelength impedance converter can be adjusted to have a desired power distribution ratio, and the loss is less than that of the parallel feed structure, and it is easier to manufacture than the serial feed structure. In addition, it has all the advantages of parallel feed structure and serial feed structure, and can achieve a desired power share ratio compared with a parallel feed structure. As compared with a serial feed structure in which power is distributed in only one direction, power is distributed in both directions The ratio of the power supplied to each patch antenna can be adjusted as desired.

The present invention has been described with reference to the preferred embodiments. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the present invention is defined by the appended claims rather than by the foregoing description, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

100, 2300: Microstrip patch array antenna
110: substrate
120: radiating element
125, 2320:
130, 2340:
140: Feeding network
150, 2350:
2310: first substrate
2330: second substrate
2360: Ground plane
2370: Slot

Claims (12)

Board;
A radiation part formed on an upper surface of the substrate and in which a plurality of radiating element rows including a plurality of radiating elements arranged in a first direction are arranged in a second direction;
And a transmission line formed on an upper surface of the substrate and symmetrical in the up, down, left, and right directions around a power feeding part for feeding power, and transmitting power from the power feeding part to each radiating element; And
And a ground portion formed on a lower surface of the substrate,
The parallel feed system and the serial feed system are applied to the feed network,
Wherein each of the plurality of radiating element rows includes N radiating elements, wherein the radiating part is configured in an array form of NXM (N, M is a natural number) radiating elements,
A plurality of λ / 4 impedance converters are provided in the transmission line of the power supply network, a characteristic impedance value of the λ / 4 impedance converter is adjusted to adjust a voltage division ratio of each output port,
Wherein the radiating element comprises a &lt; RTI ID = 0.0 &gt; 4x4 &
And two λ / 4 impedance converters are provided between the output ports connecting the radiating elements arranged in the first direction,
Wherein when the voltage division ratio is 1: 5: 5: 1, the voltage distribution ratio of the parallel feed method and the serial feed method is 1: 5. delete The method according to claim 1,
Wherein the radiating element is a microstrip patch,
Wherein the microstrip patch has a width and a length of 9 mm. The method according to claim 1,
Wherein the feed network has a center frequency of 10.5 GHz and the electrical length of the line connecting each radiating element is an antenna operating frequency wavelength (?). delete The method according to claim 1,
The power supply network includes:
And a parallel feed line portion connected to the first and second serial feeders in parallel with the additional? / 4 impedance converter, wherein the first and second serial feeders have at least one? / 4 impedance converter and are symmetrical to each other. A microstrip patch array antenna. The method according to claim 1,
Wherein the bandwidth is extended by adjusting a length of a transmission line connected to the feeding part in the feeding network or changing a line width of a transmission line connected to each radiating element. 8. The method of claim 7,
The power supply network includes:
A meander line is added on both sides of the feeding part to increase the length of the transmission line to increase the bandwidth, and the meander line includes a curved shape. A first substrate;
A radiating element formed on an upper surface of the first substrate and having a plurality of radiating element rows arranged in a second direction including a plurality of radiating elements arranged in a first direction;
A ground plane in which a plurality of slots are formed to face the position of the radiating element of the radiating part;
A second substrate on which the ground plane is formed; And
And a feed line formed on the lower surface of the second substrate and symmetric with respect to the feed part for feeding power and transmitting the power from the feed part to each radiating element,
The parallel feed system and the serial feed system are applied to the feed network,
Wherein each of the plurality of radiating element rows includes N radiating elements, and NXM (N, M is a natural number) radiating elements are arranged in an array form,
A plurality of λ / 4 impedance converters are provided in the transmission line of the power supply network, a characteristic impedance value of the λ / 4 impedance converter is adjusted to adjust a voltage division ratio of each output port,
Wherein the radiating element comprises a &lt; RTI ID = 0.0 &gt; 4x4 &
And two λ / 4 impedance converters are provided between the output ports connecting the radiating elements arranged in the first direction,
Wherein when the voltage division ratio is 1: 5: 5: 1, the voltage distribution ratio of the parallel feed method and the serial feed method is 1: 5. delete 10. The method of claim 9,
The power supply network includes:
And a parallel feed line portion connected to the first and second serial feeders in parallel with the additional? / 4 impedance converter, wherein the first and second serial feeders have at least one? / 4 impedance converter and are symmetrical to each other. A microstrip patch array antenna. 10. The method of claim 9,
Wherein the bandwidth is extended by adjusting a length of a transmission line connected to the feeding part in the feeding network or changing a line width of a transmission line connected to each radiating element.

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