Description

ANTENNA GAIN ADJUSTING MEMBER AND METHOD FOR OPTIMALLY ADJUSTING ANTENNA RECEIVING ANGLE

USING THE SAME

Technical Field

[1] The present invention relates to an antenna gain adjusting member and a method for optimally adjusting an antenna receiving angle using the same, and more particularly, to an antenna gain adjusting member which reduces a gain when an antenna is installed so that the antenna can be installed with an optimal receiving angle. Background Art

[2] As a satellite antenna used to transmit and receive satellite signals to and from a satellite in a relay satellite communication, a parabolic antenna formed of a circular reflective body is mainly used.

[3] It is difficult for a consumer to install a conventional parabolic antenna because it is bulky and heavy and should be installed to have a directivity toward a satellite. Therefore, the consumer requests an expert who knows how to install a reflective antenna and thus consumes an extra installing cost. Also, as such an antenna is installed outside, under a bad weather condition such as typhoon and rainstorm, a reception performance may deteriorate or a receiving angle may change due to any external shock. Under the bad weather condition or if the receiving angle changes, the performance of receiving satellite signals from a satellite deteriorates, which results in degraded image quality of a satellite broadcast or causes viewers not to watch the satellite broadcast.

[4] As a solution for the problem of the parabolic antenna, a planar antenna has been developed. The planar antenna is an array antenna that has a plurality of small antennas arranged on a plane in a lattice pattern. The planar antenna has a good reception performance since, while it has a small size compared to the parabolic antenna, it exhibits a large gain and a low directivity. Accordingly, unlike the parabolic antenna, it is easy to receive satellite signals even if the planar antenna does not have an accurate receiving angle. Therefore, consumers can easily and simply install the planar antenna without requesting an expert and thus an extra installing cost is not required.

[5] Since the planar antenna can receive satellite signals regardless of whether or not it is installed with an accurate receiving angle, the consumer may not set an optimal angle to receive the satellite signals. In this case, the planar antenna exhibits good image quality at ordinary times, but, if a weather condition becomes worse due to typhoon or rainstorm or if the receiving angle changes due to an external shock, image quality of a

satellite broadcast is degraded. [6] Therefore, there has been a demand for a method of installing a planar antenna with an accurate receiving angle, and this method may be achieved by providing a configuration of reducing an antenna gain such that image quality changes sensitively depending on the receiving angle of the planar antenna.

Disclosure of Invention

Technical Problem [7] Accordingly, an object of the present invention is to provide an antenna gain adjusting member intended to reduce an antenna gain and thus allow the antenna to be installed with an optimal receiving angle, and a method for optimally adjusting an antenna receiving angle using the same.

Technical Solution [8] The above object is achieved by providing an antenna gain adjusting member which is removably mounted on a front surface of an antenna and is capable of reducing a gain of a mounted antenna. [9] The gain adjusting member may be a shielding screen coated with a conductive material. [10] The gain of the antenna may be adjusted according to at least one of a size of the shielding screen and a density of the conductive material. [11] The gain adjusting member may be a shielding filter which has a plate shape and is made of a conductive material. [12] The shielding filter may shield an entire front surface of the antenna and the gain may be adjusted according to a size of the shielding filter. [13] The above object is also achieved by a method for optimally adjusting a receiving angle of an antenna, the method including mounting a gain adjusting member on a front surface of the antenna, connecting the antenna to an output device, and based on image quality of an image displayed through the output device, adjusting a receiving angle of the antenna. [14] The adjusting operation may set the receiving angle when good image quality of the image is obtained.

Advantageous Effects

[15] As described above, according to the present invention, since a receiving angle of a planar satellite antenna is accurately set, a viewer can watch a satellite broadcast of good image quality even if the receiving angle changes due to a bad weather condition or an external shock.

[16] Also, while the invention has been shown and described with reference to certain detail embodiments thereof, it will be understood by those skilled in the art that they

are merely exemplary and various changes may be made therein without departing from the technical idea of the invention. Therefore, the scope of the present invention is not limited to the described embodiment and should be defined by the appended claims and the full scope of equivalents thereof. Brief Description of the Drawings

[17] Fig. 1 is a perspective view illustrating a planar satellite antenna according to an exemplary embodiment of the present invention;

[18] Fig. 2 is an exploded perspective view illustrating respective layers for the planar satellite antenna of Fig. 1;

[19] Fig. 3 is a perspective view illustrating a gain adjusting member mounted on the planar satellite antenna of Fig. 1 according to an exemplary embodiment of the present invention;

[20] Fig. 4 is a perspective view illustrating a gain adjusting member mounted on the planar satellite antenna of Fig. 1 according to another exemplary embodiment of the present invention; and

[21] Fig. 5 is a flowchart illustrating a process of optimally adjusting a receiving angle of a planar satellite antenna using a gain adjusting member according to an exemplary embodiment of the present invention.

[22] <Description of Signs for Main Parts of the Drawings>

[23] 1: planar satellite antenna 80: shielding screen

[24] 85: conductive material 90: shielding filter

Best Mode for Carrying Out the Invention

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

[26] The present invention relates to an antenna gain adjusting member and a method for optimally adjusting an antenna receiving angle using the same. The antenna gain adjusting member is temporarily mounted on a planar satellite antenna when the antenna is installed and reduces an antenna gain such that the antenna is installed with an accurate receiving angle.

[27] More specifically, the present invention allows a user to find an optimal receiving angle when installing an antenna, using an antenna gain adjusting member mounted on the antenna to reduce an antenna gain. The antenna gain adjusting member according to an exemplary embodiment of the present invention is mounted on an antenna to reduce the gain of the antenna. Preferably, the gain adjusting member is configured to obtain a reference antenna gain (e.g. an antenna gain capable of providing good image quality) only if an antenna is installed with an optimal receiving angle.

[28] For example, it is assumed that an antenna should have a gain of 2OdB in order to

obtain good image quality and that an antenna on which the gain adjusting member according to the exemplary embodiment of the present invention is to be mounted has the followings gains for 3 (three) directions (angles A, B, C from the North in a clockwise direction), which are all greater than 2OdB: [29] Table 1

[Table 1] [Table ]

[30] The gain adjusting member according to the exemplary embodiment of the present invention should be configured to make the antenna gains for angles A and C below 2OdB and to make the antenna gain for angle B above 2OdB. The gain adjusting member of such a configuration is mounted on an antenna and allows a user to find an optical antenna receiving angle while viewing a monitor which is an output device connected to the antenna.

[31] In the following exemplary embodiment, the gain adjusting member is mounted on a planar satellite antenna shown in Fig. 1 by way of an example. However, this should not be considered as limiting. For example, the gain adjusting member can be applied to any type of antenna if only the antenna has an antenna main emission beam of a wide width.

[32] Fig. 1 is a perspective view illustrating a planar satellite antenna according to an exemplary embodiment of the present invention, and Fig. 2 is an exploded perspective view illustrating respective layers for the planar satellite antenna of Fig. 1.

[33] The planar satellite antenna 1 shown in Fig. 1 has a parallelepiped shape of a predetermined thickness, and includes a horn 10 through which a satellite signal is input and output, a first polarization guide 30 for guiding a vertical polarization i.e. a first polarization of the satellite signal input and output through the horn 10, and a second polarization guide 50 for guiding a horizontal polarization i.e. a second polarization of the satellite signal input and output through the horn.

[34] The planar satellite antenna 1 is formed of several small antennas which are arranged along row and column directions, and each small antenna includes four (4) horns 10, a single first polarization guide 30, and a single second polarization guide 50.

[35] Also, the planar satellite antenna 1 includes a plurality of layers which are layered one on another to form the horns 10, the first polarization guide 30, and the second po-

larization guide 50, and the plurality of layers includes a first layer 100, a second layer 150, a third layer 200, a fourth layer 250, and a fifth layer 300 as shown in Fig. 2.

[36] The first layer 100 is formed of a splitter 70 of a lattice pattern and the splitter 70 includes a plurality of ribs 75 which are arranged in row and column directions. The ribs 75 are arranged such that a single small antenna having four (4) horns 10 is divided into sixteen (16) areas.

[37] The second layer 150 includes inclined portions 15 of the horns 10 which are tapered inwardly and ledges 17 which protrude inwardly from ends of the inclined portions 15. The inclined portions 15 are formed on a plane side of the first layer 100 and the ledges 17 are formed on a bottom side of the first layer 100.

[38] The third layer 200 forms polarization filtering units 20 connected to the ledges 17 formed on the second layers 150. The polarization filtering units 20 penetrate through areas adjacent to corners of the second layer 150. The polarization filter units 20 includes steps 25 and protuberances 19 which are formed inside thereof.

[39] The third layer 200 forms on a bottom thereof upper portions of 1st through 4th guide tubes 31, 32, 33, 34 forming the first polarization guide 30, of 1st and 2nd intermediate tubes 35, 40, of a 1st mixing tuber 45, and of a discharge tube 48.

[40] The fourth layer 250 forms on a top thereof a lower portion of the first polarization guide 30, and forms on a bottom thereof an upper portion of the second polarization guide 50. The polarization filtering units 20 penetrate through the fourth layer 250.

[41] That is, the fourth layer 250 forms on the top thereof lower portions of the 1st through 4th guide tubes 31, 32, 33, 34 of the first polarization guide 30, of the 1st and 2nd intermediate tubes 35, 40, of the 1st mixing tube 45, and of the discharge tube 48. Also, the fourth layer 250 forms on the bottom thereof upper portions of 3rd and 4th intermediate tubes 55, 60 forming the second polarization guide 50 and of a 2nd mixing tube 65.

[42] The fifth layer 300 forms a lower portion of the second polarization guide 50. The fifth layer 300 forms the second polarization guide 50 in cooperation with the fourth layer 250, and also forms 1st through 4th direction conversion units 51, 52, 53, 54, 3rd and 4th intermediate tubes 55, 60, and the 2nd mixing tube 65. Also, the 1st through the 4th direction conversion units 51, 52, 53, 54 of the fifth layer 300 each has a protruding piece 68 and a reflective surface 69 for converting an advancing direction of the second polarization.

[43] Fig. 3 is a perspective view illustrating a gain adjusting member mounted on the planar satellite antenna 1 of Fig. 1 according to an exemplary embodiment of the present invention.

[44] A gain adjusting member 80, 90 according to an exemplary embodiment of the present invention is used to reduce a gain of the planar satellite antenna 1 when it is

installed on a front surface of the planar satellite antenna 1, and includes a flat shielding screen 80 and a conductive material coated over the shielding screen 80.

[45] The shielding screen 80 is made of an insulating material such as sponge, Styrofoam, paper, plastic resin, wood, or ceramic. In this embodiment, the shielding screen 80 is made of sponge. As shown in Fig. 3, the shielding screen 80 may be fabricated with the same or smaller size as or than that of the front surface of the planar satellite antenna 1. Also, the shielding screen 80 has a thickness of about 5- 10mm.

[46] As the conductive material 85 coated over the shielding screen 80, a carbon may be used. Also, other conductive materials 85 may be used. For example, silver (Ag), plumbum (Pd), platinum (Pt), nickel (Ni), or copper (Cu) may be coated as the conductive material 85. A single conductive material 85 may be used or a compound of two or more conductive material 85 may be used.

[47] If the shielding screen 80 coated with the conductive material 85 is mounted on the front surface of the planar satellite antenna 1, some of satellite signals are not guided to the horns 10 and instead travel along the conductive material on the shielding screen 80, so that the gain of the planar satellite antenna 1 is reduced. The shielding screen 80 is removably mounted on the planar satellite antenna 1. That is, according to circumstances, the shielding screen 80 is mounted on or dismounted from the antenna 1.

[48] Herein, the gain of the planar satellite antenna 1 is adjusted by controlling the density of the conductive material 85 coated over the shielding screen 80. That is, as the density of the conductive material 85 increases, the degree by which the conductive material can block the satellite signals increases and thus the gain of the planar satellite antenna 1 is relatively more reduced. In this case, the gain of the planar satellite antenna 1 is reduced by more than 2~3dB. On the other hand, as the density of the conductive material 85 decreases, the gain of the planar satellite antenna 1 is relatively less reduced, and in this case, the gain is reduced by less than or equal to 2~3dB.

[49] According to an exemplary embodiment of the present invention, the density of the conductive material 85 coated over the shielding screen 80 is adjusted such that the gain of the antenna 1 is greater than a reference antenna gain only if the antenna 1 is installed with an optimal receiving angle.

[50] In this description, a "reference antenna gain" refers to a degree of good image quality that a user feels when viewing a monitor outputting a broadcast signal received from the installed antenna.

[51] Also, an "front surface" of antenna refers to a surface through which the antenna transmits and receives signals.

[52] Also, the gain of the planar satellite antenna 1 is adjustable according to the size of the shielding screen 80. For example, if the size of the shielding screen 80 is equal to the front surface of the planar satellite antenna 1, the gain of the planar satellite

antenna 1 can be significantly reduced. On the other hand, if the size of the shielding screen is reduced, the gain of the planar satellite antenna 1 is relatively less reduced.

[53] That is, the shielding screen 80 according to an exemplary embodiment of the present invention is embodied by two cases as follows:

[54] 1) If the size of the shielding screen 80 is equal to or larger than that of the antenna 1 and thus covers the entire antenna 1, the gain of the antenna 1 is adjusted by controlling the density of the conductive material 85. As the density of the conductive material 85 decreases, the antenna gain becomes similar to that of the case where the shielding screen 80 is not mounted on the antenna 1, and as the density of the conductive material 85 increases, the gain of the antenna 1 is reduced.

[55] 2) If the size of the shielding screen 80 is smaller than that of the antenna 10, the gain of the antenna 1 is adjusted by controlling the density of the conductive material 85 likewise, and the size of the shielding screen 80 contributes to adjusting the gain of the antenna 1.

[56] The gain adjusting member 80, 90 formed of the above-described shielding screen 80 is installed on the front surface of the antenna 1 to reduce the gain of the planar satellite antenna 1.

[57] As the gain of the planar satellite antenna 1 is reduced as described above, unlike the prior art, a good satellite signal reception can be achieve only if a receiving angle of the antenna falls within an acceptable range in a direction of a satellite. Therefore, a consumer can set the location of the planar satellite antenna 1 with an accurate receiving angle compared to the conventional one.

[58] Fig. 4 is a perspective view illustrating a gain adjusting member mounted on the planar satellite antenna 1 according to another exemplary embodiment of the present invention.

[59] The gain adjusting member 80, 90 according to another exemplary embodiment of the present invention is a shielding filter 90 made of a conductive material. The conductive material used to manufacture the shielding filter 90 includes aluminum (Al), silver (Ag), plumbum (Pd), titanium (Pt), nickel (Ni), copper (Cu), and the shielding filter 90 is formed of any one of these conductive materials or an alloy of two or more conductive materials.

[60] The shielding filter 90 is of an elongated plate type and has a size such that it shields a part of the planar satellite antenna 1. For example, if the planar satellite antenna 1 has a size corresponding to 12*24 horns 10, the shielding filter 90 is manufactured to shield the horns 10 of 2-4 rows. That is, the shielding filter 90 has a width and a length which correspond to multiples of each horn 10. For example, if the planar satellite antenna 1 has 12*24 horns 10, the shielding filter 90 has a width 2-8 times the width of the horn 10 and a length 12-24 times the width of the horn 10.

[61] If the size of the shielding filter 90 is adjusted in the above manner, the number of horns 10 that can be shielded is changed and in this manner a gain of the planar satellite antenna 1 is adjusted. That is, as the number of horns 10 that can be shielded by the shielding filer 90 increases, the degree by which the gain of the planar satellite antenna 1 is reduced increases, and as the number of horns 10 that can be shielded by the shielding filter 90 decreases, the degree by which gain of the planar satellite antenna 1 is reduced decreases.

[62] The shielding filter 90 is mounted on a front surface of the planar satellite antenna 1.

At this time, the shielding filter 90 can reduce the gain of the antenna 1 at any position of the front surface of the planar satellite antenna 1.

[63] In the above embodiment, the shielding filter 90 is of an elongated plate type.

However, the shielding filter 90 may be formed in any configuration such as a crisscross or a picture frame having a central opening.

[64] A process of optimally adjusting a receiving angle of the antenna using the gain adjusting member 80, 90 which is embodied as the shielding screen 80 or the shielding filter 90 will now be described with reference to Fig. 5.

[65] Initially, the shielding screen 80 or the shielding filter 90 is attached to the front surface of the planar satellite antenna 1 (S501). Since the shielding screen 80 or the shielding filter 90 is temporarily mounted only when the planar satellite antenna 1 is installed, it may be attached using a sticker, a scotch tape, or a double sided tape.

[66] Then, the planar satellite antenna 1 is connected to an output device of a computer or a television or a dedicated monitor for outputting a broadcast signal (S502), and the front surface of the planar satellite antenna 1 is arranged, oriented toward a satellite.

[67] Next, a user adjusts a wave angle and an azimuth of the planar satellite antenna 1 while monitoring image quality of an image displayed on the monitor. The user finds a position providing good image quality by moving the planar satellite antenna 1 vertically and horizontally (S503). The good image quality refers to a degree of easiness and comport that the user feels when viewing an image.

[68] If a position providing good image quality is found, the planar satellite antenna 1 is fixed to the position (S504). Next, the shielding screen 80 or the shielding filter 90 is dismounted from the planar satellite antennl (S505).

[69] As described above, the gain adjusting member 80, 90 using the shielding screen 80 or the shielding filter 90 is attached to the front surface of the planar satellite antenna when the antenna is installed, and plays a role of reducing the gain of the antenna. Since the receiving performance of the planar satellite antenna 1 is lowered due to the presence of the gain adjusting member 80, 90, a good satellite signal reception is achieved only if the receiving angle of the antenna falls within an acceptable range in a direction of the satellite. Accordingly, the receiving angle of the planar satellite

antenna 1 is more accurately set, and even if the receiving angle changes due to a bad weather condition such as typhoon or rain storm or due to an external shock, a large gain of the planar satellite antenna 1 is obtained and a good reception performance is achieved. Thus, image quality deterioration does not occur. That is, a viewer can always watch a satellite broadcast of good image quality.