KR100726025B1 - Vehicle-mounted microstrip patch antenna for receiving satellite digital multimedia broadcasting signal - Google Patents

Abstract

The present invention relates to a satellite DMV onboard antenna, comprising: a patch (110) in the form of a square metal plane; A plurality of plates (120) attached to the bottom surface of the patch in a square strip shape, the corner portions of which are spaced apart at predetermined intervals; A square ground plate 130 electrically connected to the patch; And a dielectric 140 filled between the patch and the plate. It consists of.

According to the present invention, a vehicle-mounted antenna for satellite DMB (DMB) can be provided using a beam pattern capable of receiving a satellite signal regardless of the vehicle position and the starting position.

Microstrip, Antenna, Dielectric, DMB, Vehicle

Description

VEHICLE-MOUNTED MICROSTRIP PATCH ANTENNA FOR RECEIVING SATELLITE DIGITAL MULTIMEDIA BROADCASTING SIGNAL

1 is an illustration of an onboard satellite DMB antenna having inverse umbrella radiation pattern characteristics.

Figure 2a is a diagram showing the structure of a square one-wavelength microstrip antenna according to an embodiment of the present invention.

Figure 2b is a graph showing the return loss measured by using a square one-wavelength microstrip antenna according to an embodiment of the present invention.

Figure 2c is a graph showing a radiation pattern measured using a square 1 wavelength microstrip antenna according to an embodiment of the present invention.

3 is a view showing an antenna with a plate configured in a circular shape in a one-wavelength microstrip antenna according to an embodiment of the present invention.

4 is a view showing a patch configured in a folded shape in a one-wavelength microstrip antenna according to an embodiment of the present invention.

5A is a diagram showing the structure of a one-wavelength microstrip antenna with a plate attached thereto.

FIG. 5B is a graph showing return loss measured using a one-wavelength microstrip antenna with a plate; FIG.

6A is a diagram showing the structure of a 1/2 wavelength microstrip antenna using a plate;

6B is a graph showing a change in resonant frequency of a 1/2 wavelength microstrip antenna using a plate;

FIG. 7 is a graph showing the E-plane radiation pattern for change in visible length for a miniaturized one wavelength microstrip antenna. FIG.

8A and 8B are graphs showing radiation patterns for changes in reflector side lengths.

9A is a diagram showing a structure of a comparative example.

9B is a graph showing return loss measured using a comparative example.

9C is a graph showing a radiation pattern measured using a comparative example.

The present invention relates to an in-vehicle antenna for satellite DMB, and more particularly, to an in-vehicle antenna for satellite DMB having an inverse umbrella type radiation pattern in a satellite direction regardless of vehicle movement when used for satellite reception. It is about.

In the related art, a number of applications have been filed and registered in addition to Korean Patent Application Publication No. 2003-0070576 (hereinafter referred to as "prior patent") with respect to a vehicle-mounted antenna.

The above patent discloses an antenna for satellite broadcasting reception of a vehicle, comprising: a feed line coupled to a lower surface of the first dielectric between a lower surface of the first dielectric and an upper surface of the first form; A ground conductor portion having an opening coupled between an upper surface of the first dielectric and a lower surface of the second dielectric; A patch portion coupled to an upper surface of the second dielectric between the upper surface of the second dielectric and the lower surface of the second foam and electrically connected to the feed line; A third dielectric coupled to the top surface of the second foam; Characterized in that it comprises a.

However, when the prior patent is used for satellite reception, there is a problem in that it cannot provide a high quality broadcast service because the beam is not concentrated in the satellite direction and thus the satellite signal cannot be received without disconnection.

In addition, when the prior patent is used for the base station repeater, it is not suitable for the base station repeater because it does not minimize the electromagnetic waves generated at the bottom of the repeater antenna and adversely affect the human body and the environment.

The present invention is to solve the above problems, by using the radiation characteristics of the microstrip patch antenna has a non-directional radiation pattern characteristic in the azimuth direction, when used for satellite reception a certain elevation angle (위성, Elevation angle) When the beam is concentrated in the direction and the antenna is reversed to be used for the base station repeater, the base station repeater has a null point below the center of the antenna to minimize the reflection from the ground. Another object of the present invention is to provide a vehicle antenna for a satellite DMB (DMB) having an inverse umbrella radiation pattern capable of minimizing an electromagnetic wave effect near a repeater.

In accordance with one aspect of the present invention, a square 1 wavelength microstrip antenna (100) includes: a patch (110) in the form of a square metal plane; A plurality of plates (120) attached to the bottom surface of the patch in a square strip shape, the corner portions of which are spaced apart at predetermined intervals; A square ground plate 130 electrically connected to the patch; And a dielectric 140 filled between the patch and the plate. It includes.

Preferably, the resonant frequency and the antenna visible length are controlled by increasing or decreasing the number of the plates attached at right angles in a state spaced at the same distance from the bottom surface of the patch.

In addition, the patch and the ground plate is preferably connected using a one-point feeding method, it is characterized in that it is electrically connected through the coupling means (B).

Also preferably, the dielectric is characterized in that to perform the function of preventing the plate and the ground plate electrically connected.

In addition, the plate and the ground plate is characterized in that the spaced apart at a predetermined interval.

In addition, miniaturization is made by adjusting the number or length of the plates according to the increase and decrease of the dielectric constant of the dielectric.

In addition, the plate is preferably smaller as the open edge portion closer to the feed point (A), characterized in that configured in a rectangular shape.

In addition, the patch is preferably characterized in that the circular, folded shape or a planar shape by adjusting the dielectric constant.

And preferably the patch and plate is characterized in that the metal material.

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

Before describing the present invention in detail, it should be noted that the detailed description of known functions and configurations related to the present invention is omitted if it is determined that the gist of the present invention may unnecessarily obscure the subject matter of the present invention. .

A structure and features of a vehicle-mounted antenna for satellite multimedia broadcasting (DMB) using a square (length 0.7λ × 0.7λ) one-wavelength microstrip antenna according to an embodiment of the present invention. A description with reference to 1 to 2c as follows.

1 is a view showing a vehicle-mounted satellite DMB (DMB) antenna having an inverse umbrella radiation pattern characteristic according to an embodiment of the present invention, Figure 2a is a square 1 wavelength microstrip antenna according to an embodiment of the present invention 2B is a graph showing a return loss measured by using a square 1 wavelength microstrip antenna according to an embodiment of the present invention, and FIG. 2C is a square 1 wavelength micro wave according to an embodiment of the present invention. FIG. 3 is a graph illustrating a radiation pattern measured using a strip antenna. FIG. 3 is a diagram illustrating an antenna with a plate formed in a circular shape in a one-wavelength microstrip antenna according to an embodiment of the present invention. In the one-wavelength microstrip antenna according to the embodiment of the present invention, a patch having a folded shape is shown. It is a view.

As shown in FIG. 2A, the square 1-wavelength microstrip antenna 100 according to the exemplary embodiment of the present invention includes a patch 110, a plurality of plates 120, a ground plate 130, and a dielectric 140. do.

The patch 110 is a square metal plate, and in the present embodiment, the width W ₁ × length L ₁ will be set to 73 mm, respectively, but the present invention is not limited thereto. As shown in FIG. 4, it may be configured in a circular or folded shape and a planar shape by controlling the dielectric constant.

In addition, each of the plurality of plates 120 is made of a metal material and has a square strip shape at predetermined intervals on the bottom surface of the patch 110, the corner portions of which are opened at a predetermined interval, and the opening portions are close to the feed point A. FIG. It is configured to become smaller. In this embodiment, the plate 120 has a rectangular shape, the number of which is six for each side of the square patch 110, the width (L ₂ ) will be set to a size of 8mm, but the present invention is limited thereto. no.

In addition, the ground plate 130 is a metal plate, and is electrically connected to the patch 110 to perform a normal grounding function. More specifically, the ground plate 130 is connected to the patch 110 through a coupling means (B) of a conductive tablet material as shown in FIG. 2A in a so-called one-point feeding method. .

In addition, the dielectric 140 is filled between the patch 110 and the plurality of plates 120 to allow the plate 120 to maintain a circular shape, and the plate 120 may include a ground plate 130. ) To support the electrical connection. That is, the plate 120 is in an electrically coupled state with the patch 110. In the present embodiment, the width W ₁ × height H ₁ of the dielectric 140 is 73 mm × 9 mm and the dielectric constant ε _r ) will be set to 1.06, but the present invention is not limited thereto.

The measurement results of the properties of the forward 1 wavelength microstrip antenna with a plate having a center frequency of 2.6425 GHz according to an embodiment of the present invention having the above-described configuration will be described with reference to FIGS. 2B to 2C.

As shown in FIG. 2B, the return loss is -12 dB, and the -10 dB bandwidth is 78.8 MHz (3%). For reference, in the forward 1 wavelength microstrip antenna having the plate attached by using this characteristic, as shown in FIG. 2C, after changing from 0 ° to 180 ° in the xy plane at 45 ° intervals Looking at the radiation pattern, as shown in Table 1 below, that is, the gain is 1.32 dBd relative to the dipole antenna when the angle is 0 degrees, the elevation angle is 51 degrees, and the half power beam width (HPBW) is It appears at 56˚.

Azimuth angle φ in x-y plane 0 ° 45 ° 90 ° 135 ° Gain (dBd) 1.32 1.57 0.58 1.21 Elevation angle (˚) 51 58 53 57 HPBW (˚) 56 60 56 61 Elevation angle Gain (dBd) from 42 ° to 43 ° 0.8 One 0.2 0.6

Therefore, the plate-mounted forward microstrip antenna is miniaturized to 0.7λ of visible length, and the gain is 1.32dBd relative to the dipole antenna when the azimuth angle φ is 0˚, the elevation angle of the main beam is 51˚, and the HPBW Since half power beam width is 56 °, it can be suitable as an onboard antenna for satellite DMB.

In addition, when the elevation angle is 42 ° to 43 °, the gain maintains stable inverse umbrella pattern characteristics with a deviation of 0.65 dBd ± 0.4 dB on average.

Hereinafter, specific and characteristic advantages of the microstrip antenna according to the present invention described above will be described with reference to the following experimental examples and the accompanying drawings.

Experimental Example

As described above, the physical properties of the experimental example of the microstrip antenna will be described with reference to FIGS. 5A to 8B.

FIG. 5A is a diagram showing the structure of a one-wavelength microstrip antenna with a plate attached thereto, and FIG. 5B is a graph showing the return loss measured using a one-wavelength microstrip antenna with a plate attached thereto, and FIG. FIG. 6B is a graph showing a change in resonant frequency of a 1/2 wavelength microstrip antenna using a plate, and FIG. 7 is a change in visible length in a miniaturized 1 wavelength microstrip antenna. 8A and 8B are graphs showing radiation patterns for changes in reflector side lengths.

As shown in FIG. 5A, a one-wavelength microstrip antenna having a plate attached thereto is composed of a rectangular metal patch, a plurality of plates, a ground plate connected by a one-point feeding method, and a dielectric.

The center frequency having the above-described configuration is 2.6425 GHz, and the patch size is 50 mm × 52 mm in width (W ₂ ) × length (L ₃ ) and 50 mm × 8 mm in width (W ₂ ) × length (L ₅ ) The ground plate was set to a square having a width (W ₃ ) x length (L ₄ ) of 300 mm × 300 mm. The dielectric properties of the one-wavelength microstrip patch antenna with a plate designed with a width (W ₂ ) × height (H ₂ ) of 50 mm × 9 mm and a dielectric constant (ε _r ) of 1.06 will be described with reference to FIG. 5B. Is as follows.

The one-wavelength microstrip antenna to which the plate is attached is a one-wavelength microstrip antenna to which the plate is attached when the visible length is 0.5λ when nine plates are attached at right angles to the bottom surface of the patch at equal intervals. It is possible to miniaturize and the angle between the two main beams is greatest.

In this case, the return loss is -27.9dB, the gain has a gain of 7.69dBd based on the dipole antenna, the HPBW (Half Power Beam Width) of one main beam is 48˚, and the angle between the two main beams is 106 degrees, and an elevation angle represents 56 degrees.

On the other hand, when filling the void space between the patch and the ground plane with a dielectric material, increasing the dielectric constant reduces the number or length of the plate, while decreasing the dielectric constant can be miniaturized by increasing the number or length of the plate Do. That is, miniaturization of the antenna can be realized by adjusting the number or length of the plates according to the increase and decrease of the dielectric constant.

For reference, the reason for limiting the overall outline of the microstrip antenna to the square is that the microstrip antenna according to the embodiment of the present invention is a reverse umbrella by increasing or decreasing the number of plates rather than by the difference in the length and width of the patch surface. It is because it is implemented to have a radiation pattern of the type.

Hereinafter, the structure and characteristics of the 1/2 wavelength microstrip antenna using the plate will be described with reference to FIGS. 6A and 6B.

As shown in FIG. 6A, a half-wavelength microstrip antenna using a plate has a center frequency of 2.6425 GHz, a patch width (W ₄ ) × length (L ₆ ) of 90 mm × 81.5 mm, and a dielectric constant (ε). _The dielectric with _r ) is 1.06 is set to a width W ₄ of 90 mm and a height H ₃ of 9 mm.

In the 1/2 wavelength microstrip antenna having the above-described configuration, as shown in FIG. 6B, the resonant frequency is varied according to the number of plates to be attached. More specifically, as the number of plates increases, the perturbation effect and the current path increase, and the resonance frequency thereof decreases. Accordingly, the antenna can be miniaturized by narrowing the distance from the radiation aperture, and consequently, when the effect is applied to the one-wavelength microstrip antenna, the elevation angle of the main beam toward the DMB satellite can be predicted. .

Similarly, when the plate length of the above-mentioned one-wavelength microstrip antenna is increased to 2, 4, 6, 7, and 9, the visible length L ₃ is decreased by 0.1λ from 0.9 to 0.5λ, FIG. 7. As shown in FIG. 2, the angle between the two main beams increases from 63 ° to 106 ° as the visible length L ₃ decreases.

In addition, as shown in FIGS. 8A and 8B, when the antenna is used to reverse the position and the umbrella pattern is used for the repeater, the angle between the two main beam angles must be large. Set the visible length (L ₃ ) to be 0.5λ by using. Next, the size of the ground plane is changed to increase the elevation angle of the main beam, that is, the ground plane size is appropriate when changing the main beam angle because the change of the fringing area at the radiation opening is relatively large. Adjusting is somewhat advantageous.

Therefore, when the distance (ㅿ W) from the radiating aperture of the antenna to the tip of the ground plate was decreased by 10mm from 120mm to 0mm, the elevation angle of the main beam was changed from 37 ° to 90 °.

The distance from the radiation opening to the end of the ground plate, that is, ㅿ W will be described with reference to the following equation.

[Equation]

More specifically, when the distance (ㅿ W) from the radiation aperture of the one-wavelength microstrip antenna to the end of the ground plate is 0 mm, the beam becomes vertically symmetrical to maximize in the horizontal direction, but the gain is lowered. In addition, the change of main beam angle was large when ㅿ W was 10 mm or less, and there was little change in elevation angle of main beam from ㅿ W from 10 mm to 20 mm.

As described above, the antenna for satellite DMB reception according to the present invention has an elevation angle of 42 ° to 43 ° in the satellite direction. Therefore, when the visible length of the 1-wavelength microstrip antenna is set to 0.7λ, the gain is increased. It is 7.96dBd and the HPBW (Half Power Beam Width) is 48 °, so it is possible to maintain a reception level stable enough to change the elevation angle caused by the vibration of the vehicle.

Hereinafter, the physical properties of the comparative example compared to the one-wavelength microstrip antenna according to the present invention will be described with reference to FIGS. 9A to 9C.

9A is a view showing the structure of a comparative example, FIG. 9B is a graph showing the reflection loss measured using the comparative example, and FIG. 9C is a graph showing the radiation pattern measured using the comparative example.

[Comparative Example]

When the elevation angle is 42 ° to 43 ° to receive a satellite DMB signal using the microstrip antenna according to the present invention, to confirm the radiation pattern, as a comparative example, a reference linear polarization 1 wavelength micro A strip patch antenna was designed.

As shown in FIG. 9A, the microstrip patch antenna of the reference linearly polarized wave 1, which is a comparative example, has a center frequency of 2.6425 GHz, and a width (W ₅ ) × length (L ₇ ) of 50 mm × 104 mm to a patch size. The ground plate set the width (W ₆ ) × length (L ₈ ) to a square of 300 mm × 300 mm. The width W ₅ × height H _{4 of the} dielectric was 50 mm × 9 m, and the dielectric constant ε _r was set to 1.06.

As shown in FIG. 9B, the return loss is -16 dB, and the -10 dB bandwidth is 107 MHz (4%), and has a return loss characteristic for the reference linearly polarized wave 1 wavelength microstrip patch. In addition, typical half-wavelength microstrip patch antennas have a wide radiation pattern in the broadside direction. However, the one-wavelength microstrip patch antenna shows 'Null' in the broadside direction.

Also, the position of the feed point A is located at the center of the one wavelength patch, which means that the current at the bottom of the one wavelength patch is not 'Null' by the clipping current of the conductor surface at the center of the patch. This phenomenon indicates that the feed point A can be selected and realized to expand to a '+' shape or a square antenna to obtain a three-dimensional inverse umbrella beam pattern.

Reference linearly polarized wave 1 wavelength As shown in FIG. 9C, 'Null' appears in a broadside direction and maximum radiation occurs in the left and right 30 ° directions, and the reference linearly polarized wave 1 wavelength according to a comparative example is shown in FIG. 9C. The microstrip patch antenna has a gain of 7.82 dBd relative to the dipole antenna when the elevation angle is 33 °, the half power beam width (HPBW) of one main beam is 32 °, and the open angle of the two main beams is 63 °. It indicates that it is °.

Therefore, the reference linearly polarized wave 1 wavelength microstrip patch antenna is too large in size, has an elevation angle of 33 °, and if dual polarization is formed, the gain will be reduced by 3 dB, and the elevation angle is 42 ° to When the angle is 43 °, the level is further lowered, and when the elevation angle of the vehicle vibration is greater than when the angle is 42 ° to 43 °, the level decrease may be large. Therefore, when the length of the patch is one wavelength, it is disadvantageous to receive the satellite DMB signal regardless of the vehicle position and the starting position.

Accordingly, as shown in FIG. 1, when used for receiving a satellite DMB, an elevation angle having an inverse umbrella type radiation pattern in which a beam is focused in a satellite direction regardless of vehicle movement is 42 ° to 43 °. As far as possible, the on-board antenna for satellite DMB according to the present invention has been developed.

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

According to the present invention as described above, it is possible to provide a miniaturized on-board antenna for a satellite DMB (DMB) having a non-directional radiation pattern in the azimuth direction.

In addition, a vehicle-mounted antenna for satellite DMB (DMB) can be provided using a beam pattern capable of receiving a satellite signal regardless of a vehicle position and a starting position.

Claims (9)

In the square microstrip antenna 100, A patch 110 having a square metal plane shape formed of a circular shape, a folded shape, or a planar shape by adjusting the dielectric constant; A plurality of plates 120 having a square stripe shape at a predetermined interval on the bottom surface of the patch 110, the corner portions of which are opened at a predetermined interval, and the opening portion being smaller as the feed point A approaches; A square ground plate 130 connected to the patch by using a one-point feeding method, electrically connected through a coupling means (B), and spaced apart from the plate at predetermined intervals; And A dielectric (140) filled between the patch and the plate such that the plate and the ground plate are not electrically connected; Including but not limited to: The square microstrip antenna 100, According to the dielectric constant of the dielectric increase or decrease in the spaced apart at equal intervals on the bottom of the patch by adjusting the number or length of the plate attached at right angles by adjusting the resonant frequency and antenna visible length, it is characterized in that the miniaturization of the antenna Satellite DM cost onboard antenna. delete delete delete delete delete delete delete delete

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