WO2004105177A2

WO2004105177A2 - Waveguide slot antenna

Info

Publication number: WO2004105177A2
Application number: PCT/KR2004/001208
Authority: WO
Inventors: Kyung Hwan Jung
Original assignee: Microface Co., Ltd.
Priority date: 2003-05-22
Filing date: 2004-05-20
Publication date: 2004-12-02
Also published as: KR20040100328A; WO2004105177A3; KR100662733B1

Abstract

The object of this invention is to provide a waveguide slot antenna for receiving a frequency from a satellite. The antenna includes a radiating unit (10) which has a slot (13) and a radiating projection (14) to receive the frequency from the satellite. A feeder unit (20) is coupled to the radiating unit to concentrate the frequency on a location. The feeder unit is horizontally positioned, and has a predetermined beam angle to receive the frequency from the satellite. The antenna is not installed to be directed to a satellite, but is horizontally positioned to transmit or receive a frequency to or from the satellite. Further, the antenna is easily manufactured, and is constructed to freely adjust the size and height of elements to allow a complete frequency band to be received, and to concentrate frequencies on a location using a waveguide line, and to easily increase a gain.

Description

WAVEGUIDE SLOT ANTENNA

Technical Field

The present invention relates, in general, to waveguide slot antennas and, more particularly, to a waveguide slot antenna, which is constructed so that the antenna is not installed to be directed to a satellite, but is horizontally positioned to transmit or receive a frequency to or from the satellite.

Background Art

Generally, a waveguide is a kind of transmission line to guide the propagation of electromagnetic waves having a high frequency, which is higher than a microwave. The waveguide is a tube made of an electric conductor, such as copper, and guides the propagation of electromagnetic waves in a lengthwise direction of the tube. Further, the waveguide having characteristics of a high-pass filter cannot propagate electric waves with a wavelength which is longer than a cut-off wavelength. A wavelength of a wave that propagates along an axis of the waveguide is designated as a guide wavelength, and is longer than an excitation wavelength. A mode in waveguide which comprises a hollow metallic tube and serves as a kind of high-pass filter has a predetermined cut-off wavelength. A fundamental mode is determined by a size of the waveguide. In a low frequency, a transmission line having two copper lines is commonly used. Meanwhile, when the frequency becomes high, a loss of a conductor is increased due to a surface effect of the conductor, and a dielectric loss of surrounding insulating materials is increased. However, since the electromagnetic waves are propagated in the waveguide while being reflected on an inner wall of the waveguide, the waveguide has an advantage in that a loss is reduced.

Further, the waveguide is advantageous in that attenuation is relatively less as compared to a twin-lead type feeder or a coaxial cable, so that the waveguide has been used to obtain a high output in microwave transmission lines. The waveguide has various cross-sections. According to the cross-sections, there are a circular waveguide, a square waveguide, an elliptical waveguide, etc. After a dielectric material having a low loss under the high frequency was developed, a microstrip patch array antenna using a dielectric substrate has been widely spread, thus allowing a small-sized antenna to be manufactured. However, the dielectric loss inevitably is generated due to the characteristics of the dielectric substrate, and a resistance loss of the conductor is also generated, so that it is difficult to manufacture a high- gain antenna. Further, because the dielectric substrate is expensive, the microstrip patch array antenna is not widely used. There has been used a waveguide slot antenna which is constructed so that a slot is bored in a general waveguide, without using the dielectric material. Such a waveguide slot antenna has a longer history than a plane antenna using the dielectric material. However, the waveguide slot antenna is less used, in comparison with the plane antenna using the dielectric material, because the waveguide slot antenna is larger and heavier than the plane antenna, and a manufacturing process of the waveguide slot antenna is more sophisticated than the plane antenna. Further, it is more difficult to design the waveguide slot antenna, as compared to the plane antenna using the dielectric material. The waveguide slot antenna undesirably has more grating lobe. Furthermore, it is difficult to manufacture the high gain antenna. In a conventional waveguide antenna, the antenna must be directed to a satellite so as to transmit or receive a frequency to or from the satellite. Thus, the size of the antenna and a space to install the antenna are limited when manufacturing the antenna, and thus the antenna does not have various shapes. Brief Description of the Drawings

FIG. 1 is a perspective view to show a radiating unit of a waveguide slot antenna, according to the present invention; FIG. 2 is a rear view to show a feeder unit of the waveguide slot antenna, according to the present invention;

FIG. 3 is a plan view to show the feeder unit of the waveguide slot antenna, according to the present invention; FIG. 4 is a view to show a state where the radiating unit is coupled to the feeder unit of the waveguide slot antenna, according to the present invention;

FIG. 5 is a view to show another configuration of FIG. 4;

FIG. 6 is a view to show a further configuration of FIG. 4;

FIG. 7 is a plan view to show the state where n radiating units are coupled to the feeder unit of the waveguide slot antenna, according to the present invention; FIG. 8 is a view to show another configuration of FIG. 7;

FIG. 9 is a side view to show a radiating angle of the waveguide slot antenna, according to the present invention;

FIG. 10 is a view to show another configuration of FIG. 9; and FIG. 11 is a graph to show a gain of the waveguide slot antenna, according to the present invention.

*Description of reference characters of important parts* 10: radiating unit 11: body

12: radiating line 13: slot 14: radiating projection 15: mounting unit 16: mounting hole 20: feeder unit 21: feeder hole 21a: first feeder hole

21b second feeder hole 21c: third feeder hole 21d fourth feeder hole 22 : waveguide line 22a first waveguide line 22b: second waveguide line 22c third waveguide line 23: inductive post 23a first inductive post 23b: second inductive post 23c third inductive post 24: fastening hole

Disclosure of the Invention

Technical Problem

Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a waveguide slot antenna, which is easily manufactured, and is constructed to freely adjust the size and height of elements to allow a complete frequency band to be received, and constructed to concentrate frequencies on a location using a waveguide line after a signal is input from each of the elements, and constructed to easily increase a gain by increasing the array number of the elements.

Another object of the present invention is to provide a waveguide slot antenna, which has various shapes and is easily installed without any space limitations.

Technical Solution

In order to accomplish the above object, the present invention provides a waveguide slot antenna for receiving a frequency from a satellite, which includes a radiating unit having a slot and a radiating projection to receive the frequency from the satellite, and a feeder unit coupled to the radiating unit to concentrate the frequency on a location, and horizontally positioned and having a predetermined beam angle to receive the frequency from the satellite.

Further, in order to accomplish the above object, the present invention provides a waveguide slot antenna, including a body having a radiating line which longitudinally passes through the body to receive frequency from a satellite, a radiating unit including a mounting unit which is integrally provided on an end of the body and has a mounting hole to mount the body to a feeder unit, and the feeder unit having a same size as that of the radiating line of the body to receive the frequency from the satellite, and fastened to the mounting unit using a bolt.

Advantageous Effects

The effects of the waveguide slot antenna according to the present invention are as follows. The waveguide slot antenna is constructed so that the antenna is not installed to be directed to a satellite, but is horizontally positioned to transmit or receive a frequency to or from the satellite.

Further, the waveguide slot antenna is easily manufactured, and is constructed to freely adjust the size and height of elements to allow a complete frequency band to be received, and constructed to concentrate frequencies on a location using a waveguide line after a signal is input from each of the elements, and constructed to easily increase a gain by increasing the array number of the elements .

Best Mode for Carrying Out the Invention

Reference should now be made to the drawings, in which the same reference numerals are used throughout the different drawings to designate the same or similar components .

FIG. 1 is a plan view to show a radiating unit of a waveguide slot antenna, according to the present invention, FIG. 2 is a plan view to show a feeder unit of the waveguide slot antenna, according to the present invention, FIG. 3 is a front view to show the feeder unit of the waveguide slot antenna, according to the present invention, FIG. 4 is a view to show a state where two slots are formed on the radiating unit, according to the present invention; FIG. 5 is a view to show another configuration of FIG. 4, FIG. 6 is a view to show a further configuration of FIG. 4, FIG. 7 is a plan view to show the state where n radiating units are coupled to the feeder unit of the waveguide slot antenna, according to the present invention, FIG. 8 is a view to show another configuration of FIG. 7, FIG. 9 is a side view to show a radiating angle of the waveguide slot antenna, according to the present invention, FIG. 10 is a view to show another configuration of FIG. 9, and FIG. 11 is a graph to show a gain of the waveguide slot antenna, according to the present invention.

Since components of the antenna, such as an LNB or an antenna control panel, are well known in the art, the components will not be described herein, but only the construction of the antenna will be described herein.

As shown in FIGS. 1 through 11, the waveguide slot antenna includes a radiating unit 10 and a feeder unit 20. The radiating unit 10 has a slot 13 and a radiating projection 14 to receive a frequency from a satellite. The feeder unit 20 is coupled to the radiating unit 10 to concentrate the frequency on a location.^' The feeder unit 20 is horizontally positioned, and has a predetermined beam angle to receive the frequency received from the satellite. In this case, a beam angle of the frequency received from the satellite is controlled as desired by adjusting a width and a length of the slot 13, thus allowing each of countries to receive a signal of the satellite.

According to the present invention, the waveguide slot antenna includes a body 11, with a radiating line 12 longitudinally passing through the body 11 to receive the frequency from the satellite. The radiating unit 10 includes a mounting unit 15. The mounting unit 15 is integrally provided on an end of the body 11, and has mounting holes 16 to mount the body 11 to the feeder unit 20 which will be described in detail later. The feeder unit 20 has a same size as that of the radiating line 12 of the body 11 to receive the frequency from the satellite, and is fastened to the mounting unit 15 by means of bolts.

A rectangular hole is longitudinally provided on a surface of the body 11, thus providing the slot 13 to transmit or receive the frequency to or from the satellite. Further, the radiating projection 14 is provided on a side of the body 11 to adjust a receiving angle of the frequency received from the satellite. The radiating projection 14 is bent at a predetermined position, thus defining a U-shaped groove . The beam angle of the frequency received from the satellite is controlled as desired, by adjusting the width and length of the slot 13 of the radiating unit 10. Further, the beam angle of the frequency received from the satellite is controlled as desired, by adjusting a height and a width of the radiating projection 14.

A feeder hole 21 and a waveguide line 22 are provided in the . feeder unit 20 to be at a right angle with a lengthwise direction of the feeder unit 20. The waveguide line 22 is provided at a position around the feeder hole 21 to be perpendicular to the feeder hole 21.

The waveguide line 22 forms a first feeder hole 21a that is provided in the feeder unit 20 to extend inward while being at a right angle with the lengthwise direction of the feeder unit 20 on a horizontal plane. A first waveguide line 22a extends in each of opposite directions from the first feeder hole 21a to have a predetermined length, and transceives the frequency. A second feeder hole 21b is provided at a position around the first waveguide line 22a to be perpendicular to the first waveguide line 22a. A second waveguide line 22b extends in each of opposite directions from the second feeder hole 21b to have a predetermined length, and transceives the frequency. Further, a third feeder hole 21c is provided at a position around the second waveguide line 22b to be perpendicular to the second waveguide line 22b. A fourth feeder hole 2Id is provided to be perpendicular to the third feeder hole 21c, and transmits or receives the frequency to or from the satellite.

An inductive post 23 is further provided in the feeder unit 20. The inductive post 23 includes first, second, and third inductive posts 23a, 23b, and 23c that are respectively provided at centers of the first, second, and third feeder holes 21a, 21b, and 21c so as to divide the frequency into two parts.

The radiating unit 10 comprises a plurality of radiating units, and the feeder unit 20 comprises a plurality of feeder units. The feeder units 20 coupled to the radiating units 10 are arranged to face each other, thus having a symmetric structure.

Further, the feeder holes 21, the waveguide lines 22, and the inductive posts 23 are symmetrically arranged with respect to the first feeder hole 21a provided in the feeder unit 20.

The radiating unit 10 and the feeder unit 21 may be made of a metal. Alternatively, the radiating unit 10 and the feeder unit 20 may be made of synthetic resin with coating parts. The coating parts (not shown) are made of metal materials which can receive the frequency, and are coated on surfaces of the radiating unit 10 and the feeder unit 20.

The operational effects of the waveguide slot antenna according to the present invention will be described in the following.

The process of manufacturing the waveguide slot antenna is as follows . Generally, the antenna is manufactured through a casting process. Since the casting process is well known in the art, the casting process will not be described herein in detail.

The waveguide slot antenna is manufactured through the casting process or an injection molding process. In case of the injection molding process, the radiating unit 10 and the feeder unit 20 are made of synthetic resin. Subsequently, the metallic coating parts (not shown) which can receive the frequency are provided on the holes and lines of the radiating unit 10 and the feeder unit 20, that is, frequency receiving paths provided on outer and inner surfaces of the radiating unit 10 and the feeder unit 20.

The radiating unit 10 and the feeder unit 20 are made of metal or synthetic resin. After the mounting holes 16 of the mounting unit 15 which is integrally provided on an end of the radiating unit 10 are aligned with fastening holes 24 of the feeder unit 20, the radiating unit 10 is fastened to the feeder unit 20 using bolts so that the radiating unit 10 is undesirably removed from the feeder unit 20.

At this time, the radiating line 12 of the radiating unit 10 is accurately aligned with the fourth feeder hole

21d, thus allowing the satellite frequency to be smoothly transmitted from the radiating unit 10 through the feeder unit 20.

When the radiating unit 10 is fastened to the feeder unit 20, the waveguide slot antenna can receive the frequency from the satellite, although the radiating unit 10 and the feeder unit 20 are not directed to the satellite to maintain a receiving angle. That is, the frequency is received through the slot 13 of the radiating unit 10. In this case, a receiving ratio is controlled according to a size or height of the slot 13. Further, the receiving angle of the antenna is controlled according to the height or width of the radiating projection 14 provided at a position around the slot 13. Since a received frequency is varied by a width of the U-shaped groove defined by the radiating projection 14, a half-wave design of a desired frequency is allowed, and a design is executed to maintain the flatness, thus preventing irregular reflections. In this case, a depth of the U-shaped groove is a very important factor in determining a receiving band of the frequency. Further, a direction of a beam is determined by the depth of the U-shaped groove. In the present invention, the U-shaped groove has the depth as shown in the drawings, to be oriented at 45°. The direction of the beam may be changed by the depth of the U-shaped groove, etc.

Electric wave propagating characteristics are affected by the depth of the U-shaped groove, so that the antenna is designed to be lower than a desired frequency by a half wave, and the position of the slot 13 is determined according to a designed result, and a beam width is determined by the length of the slot 13. Those of skill in the art will easily manufacture the radiating projection 14 provided to adopt the above- mentioned half-wave structure. Such a construction allows the antenna to receive the frequency from the satellite, although the antenna is not directed to the satellite at a predetermined angle to receive the frequency from the satellite.

FIG. 11 shows the change of a direction of the beam receiving the frequency through the antenna that is constructed as described above. The data of the graph shown in FIG. 11 are obtained through a net analyzer.

A plurality of radiating units 10 and feeder units 20 may be coupled to each other to manufacture various kinds of antenna, as shown in FIGS. 4 through 8, without being limited to the construction having a single radiating unit 10 and a single feeder unit 20, as shown in FIG. 1.

When the antenna has the plurality of radiating units 10, the gain of the antenna is increased, thus having a higher receiving ratio.

As described above, the present invention provides a according to the present invention, it is unnecessary for the antenna to be always directed to the satellite while being at a predetermined angle with the satellite. Thus, when a satellite antenna is manufactured using the antenna of the present invention, various shapes of antennas can be manufactured. Further, the satellite antenna manufactured using the antenna of the present invention, can be utilized in various locations, including cars, buses, airplanes, trains, ships, companies, homes, offices, etc.

The present invention is not limited to the embodiments shown in the drawings. The body 11 of the radiating unit 10, the radiating projection 14, and the feeder unit 20 included in the antenna to receive a half- wave frequency may be variously modified without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

1. A waveguide slot antenna for receiving a frequency from a satellite, comprising: a radiating unit including a slot and a radiating projection to receive the frequency from the satellite; and a feeder unit coupled to the radiating unit to concentrate the frequency on a location, the feeder unit being horizontally positioned and having a beam angle of 45° to receive the frequency from the satellite.

2. A waveguide slot antenna, comprising: a body having a radiating line, the radiating line longitudinally passing through the body to receive frequency from a satellite; a radiating unit, comprising: a mounting unit integrally provided on an end of the_. body, and having a mounting hole to mount the body to a predetermined position; and a feeder unit having a same size as that of the radiating line of the body to receive the frequency from the satellite, and fastened to the mounting unit using a bolt.

3. The waveguide slot antenna according to claim 2, wherein a rectangular hole is longitudinally provided on a surface of the body, thus providing a slot to transmit or receive the frequency to or from the satellite.

4. The waveguide slot antenna according to claim 2, further comprising: a radiating projection provided on a side of the body to adjust a receiving angle of the frequency received from the satellite, the radiation projection being bent at a predetermined position thereof, thus defining a U-shaped groove .

5. The waveguide slot antenna according to claim 2, wherein the radiating unit and the feeder unit are made of either a metallic material or synthetic resin on which a metallic material is coated.

6. The waveguide slot antenna according to claim 2, wherein the feeder unit comprises: a first feeder hole provided in the feeder unit to extend inward while being at a right angle with a lengthwise direction of the feeder unit on a horizontal plane; a first waveguide line extending in each of opposite directions from the first feeder hole to have a predetermined length, and transceiving the frequency; a second feeder hole provided at a position around the first waveguide line to be perpendicular to the first waveguide line; a second waveguide line extending in each of opposite directions from the second feeder hole to have a predetermined length, and transceiving the frequency; a third feeder hole provided at a position around the second waveguide line to be perpendicular to the second waveguide line; and a^' fourth feeder hole provided to be perpendicular to the third feeder hole, and transceiving the frequency.

7. The waveguide slot antenna according to claim 2, wherein the radiating unit comprises a plurality of radiating units, and the feeder unit comprises a plurality of feeder units, so that the feeder units coupled to the radiating units are arranged to face each other, thus having a symmetric structure.

8. The waveguide slot antenna according to claim 3, wherein - the beam angle of the frequency received from the satellite is controlled, by adjusting a width and a length of the slot of the radiating unit.

9. The waveguide slot antenna according to claim 3, wherein, according to a vertical length and size of the slot provided on the body, the receiving angle of the frequency received from the satellite is controlled.

10. The waveguide slot antenna according to claim 4, wherein the beam angle of the frequency received from the satellite is controlled, by adjusting a height and a width of the radiating projection of the radiating unit.

11. The waveguide slot antenna according to claim 4, wherein the radiating projection is provided at a position around the slot provided on the surface of the body, the radiating projection being bent at a predetermined portion thereof.

12. The waveguide slot antenna according to claim 6, further comprising: an inductive post provided at a center of each of the first, second, and third feeder holes provided in the feeder unit to divide the frequency into two parts.

13. The waveguide slot antenna according to any one of claims 6 and 12, wherein the waveguide lines, the feeder holes, and the inductive posts are symmetrically arranged with respect to the first feeder hole provided in the feeder unit.