KR20090043082A - Satellite tracking antenna and method for tracking the satellite - Google Patents

Abstract

One or more antenna elements for transmitting and receiving radio waves, and a low noise amplifier and the low noise amplifier connected to each of the antenna elements so as to generate a monopulse wave and acting as an active antenna. Disclosed is a satellite tracking antenna comprising a radio frequency phase shifter (Ku-Band) connected with a.

According to the present invention, it is possible to obtain a satellite tracking antenna having a simple mechanical configuration and generating a monopulse wave without mechanical movement of the beam, thereby reducing scanning loss and reducing signal degradation.

Satellite tracking antenna, high frequency phase shifter, main reflector, sub reflector, horn copier

Description

SATELLITE TRACKING ANTENNA AND METHOD FOR TRACKING THE SATELLITE}

The present invention relates to a satellite tracking antenna, and more particularly, to a satellite tracking antenna which is installed in a moving object such as a vehicle, a ship, and an aircraft so that the location of the satellite can be tracked and the communication with the satellite can be performed efficiently even during the movement of the moving object.

In mobile vehicles, ships, aircraft, and the like, signals are often transmitted and received by satellite relay for long-range wireless communication or content reception from satellites (hereinafter referred to as "communication").

Satellite tracking antennas used for communication with satellites typically include a reflector that reflects the radio waves in order to radiate the radio waves to a long distance or to receive weak radio waves, depending on the configuration of the reflector. Cassegrain antenna, and Gregorian antenna.

The parabolic antenna communicates by arranging a radiator at the focal point of a parabolic reflector and reflecting the radio wave from the copy machine by the reflecting plate or by reflecting the radio wave to the antenna by the reflecting plate.

On the other hand, casein and gregory antennas have sub-reflectors placed at the focal point of the parabolic main reflector such that the radio wave reflected from the main reflector is concentrated through the sub-reflector to the copier or the radio wave from the copier is reflected to the main reflector. Communication takes place. Parabolic antennas are small in size but relatively short in communication distance, and therefore, a casein or antenna is mainly used for long distance communication.

In these antennas, as a copy machine, a horn copy machine (also called a feed horn) is usually employed.

On the other hand, the antenna for satellite communication needs to maximize the communication efficiency by continuously tracking the position of the satellite during the movement to maintain the antenna orientation in the direction of the satellite. In general, a monopulse method using a mono-pulse wave is used to determine the position of a satellite.

The monopulse method is a conical scanning method of determining the position of an object by rotating a beam around a boresight of an antenna. By comparing the reflected waves, the position of the object is determined based on the sum and difference of the received signals.

  Then, the direction of the antenna is changed by controlling the motor according to the position of the object thus determined.

  Conventional satellite tracking antennas include a horn copier for communication propagation, a pair of horn copiers for horizontal positioning monopulse waves, and a pair of horn copiers for vertical positioning monopulse waves. However, such an antenna includes a total of five horn copiers, which has a problem in that their size increases and manufacturing costs increase.

In order to solve this problem, Korean Patent No. 331785 of High Gain Antenna Co., Ltd. arranges the sub-reflection plate to be axially displaced from the main reflection plate and rotates the sub-reflection plate to generate horizontal and vertical monopulse waves equivalent to the horizontal and vertical monopulse waves. The technique to make is disclosed.

According to this patent, since a monopulse wave is implemented using a sub-reflective plate included in the antenna, there is no need to install a horn copier for the monopulse wave, thereby minimizing the antenna and reducing the cost. However, the antenna of High Gain Antenna Co., Ltd. has a limitation that it can be applied only to a casee grain or Gregorian antenna having a negative reflector. In addition, new mechanical components must be included to rotate the sub-reflector, so that the manufacturing cost of the antenna is reduced or the cost is increased. In addition, the life of the driving motor and the limitation of the rotational speed and vibration caused by the driving of the motor are not included. New problems arise. In particular, since the vibration generated when the reflector is moved by the motor has a great influence on the antenna characteristics, there is a problem that an additional dustproof structure is required. In addition, since the main beam is deformed to generate a monopulse wave, a scanning loss occurs.

The present invention was made in recognition of the above-described problems, and since the monopulse wave is generated at a high speed using a high frequency phase shifter implemented by a high frequency switch, it is possible to reduce the antenna manufacturing cost by not requiring additional mechanical driving components. In addition, it is an object of the present invention to provide an effective satellite tracking antenna that does not have a scanning loss and prevents signal degradation since the received signal and the control signal are processed separately without using the movement of the mechanical beam.

Another object of the present invention is to provide a conical scanning satellite tracking antenna using a monopulse wave that can be easily applied to various antenna configurations.

According to an aspect of the present invention to achieve the above object, it is composed of one or more antenna elements for transmitting and receiving radio waves, and the antenna element is connected to each one of the antenna elements so as to generate a monopulse wave, one external And a low noise amplifier (LNA) for minimizing internal thermal noise signals and amplifying a desired signal, and a high frequency phase shifter connected to the low noise amplifiers connected to the respective antenna elements.

The satellite tracking antenna according to an embodiment of the present invention further includes a main reflector having a parabolic cross section for reflecting radio waves, wherein the antenna element is preferably a horn copier. Further, the at least one horn copier may be formed by partitioning an opening of one horn copier.

The satellite tracking antenna is a sub reflector reflecting the radio waves from the horn copier to the main reflector, and may further include a sub reflector disposed on the same axis as the main reflector.

On the other hand, the antenna element is connected to a low noise amplifier to improve the noise figure (NF: noise figure), which is an element that causes system degradation of the entire antenna, and an effective antenna gain, respectively, and the low noise amplifier is Connected to a power divider, which divides the signal from the low noise amplifier into a signal receiving circuit and the high frequency phase shifter to generate a monopulse wave without affecting the carrier signal actually propagated. It is preferable.

Further, the signal distributed by the power divider is synchronized by a common oscillator, and the signal receiving circuit and the high frequency phase shifter are also included in one low noise block (LNB).

   The high frequency phase shifter may include a radio frequency (RF) switch, and the satellite tracking antenna may further include a driving unit for displacing the antenna according to the position of the satellite based on the generation of the monopulse wave.

The antenna includes four antenna elements, and the antenna elements may be arranged in the form of a 2 × 2 matrix.

According to another aspect of the present invention for achieving the above object, a satellite comprising at least one antenna element for transmitting and receiving radio waves, and a high frequency phase shifter connected to each of the antenna elements such that the antenna element generates a monopulse wave. In the location tracking method using a tracking antenna, there is provided a location tracking method for tracking the position of a satellite by selectively using two or less of the horn copiers.

According to the present invention, a high speed and various monopulse waves can be formed using a high frequency switch without the need for additional mechanical components, thereby reducing the antenna manufacturing cost. In addition, since signals are independently distributed and separated by the signal receiving circuit and the high frequency phase shifter, there is no scanning loss and signal degradation can be prevented unlike a method of moving a beam by a mechanical configuration.

In addition, according to the present invention, it is possible to easily form a monopulse wave in the specific configuration of the antenna.

DETAILED DESCRIPTION Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, which are exemplary and the present invention is not limited thereto. In particular, the following description regarding the transmission of a signal through an antenna can be similarly applied to the reception of a signal, and vice versa.

  1 is a perspective view of a satellite tracking antenna according to an embodiment of the present invention, and the overall system in which the satellite tracking antenna is implemented is shown in FIGS. 5A and 5B. The satellite tracking antenna of the embodiment according to the present invention includes a main reflection plate 100, a horn copier 300 formed on one side of the main reflection plate 100, and a sub-reflection plate that reflects signals to and from the horn copier 300. 200. Although not shown, the antenna further includes a controller and a driver for changing the orientation of the antenna according to the position of the satellite determined based on the generation of the monopulse wave.

  The main reflector plate 100 has a parabolic cross section and its surface is formed of a conductive material to concentrate and reflect incident radio waves to a focal point, or to reflect substantially parallel radio waves emitted from the focal point. By focusing the radio waves to the focal point by the main reflector, weak radio waves can be easily received, and when transmitted, radio waves can be transmitted to a long distance.

   The horn copier 300 is also called a feed horn and is a kind of antenna element for transmitting and receiving radio waves. That is, the horn copier 300 includes a signal processor (not shown) including a low noise amplifier and a power divider, a high frequency phase shifter, a high frequency mixer, a down converter, and the like, and the horn copier 300 The signal from is divided into two signals, one of which is separated into a received signal and output to the outside of the antenna. The other signal is connected to a control unit provided in the antenna and resonates with electromagnetic waves of a specific frequency to convert it into an electrical signal. Control function. The horn copier 300 is a waveguide having an opening on one side and a signal input to the other side, and the opening has a horn shape in which its area becomes larger as it moves away from the signal input side. Accordingly, radio waves may be radiated from the openings or radio waves may be received through the openings. The horn copier 300 is disposed on the focal side of the main reflector 100, that is, on the concave side of the main reflector 100 to directly transmit and receive radio waves.

   The horn copier 300 includes one or more horn copiers, in this embodiment four horn copiers 310, 320, 330, 340. Each horn copier 310, 320, 330, 340 is connected to a low noise amplifier of the signal processing section as described below, and the low noise amplifier is connected to a power divider of the signal processing section, so that the signal from the horn copier 300 is high frequency. It is distributed to the phase shifter and the signal receiving circuit. Therefore, the horn copier 300 may perform both transmission and reception of radio waves for monopulse waves in various directions and transmission and reception of radio waves for communication of data.

  Preferably the four horn copiers are arranged in the form of a 2 × 2 matrix and may all have openings of the same size so that a uniform monopulse wave is produced. In one embodiment according to the invention, the openings of the four horn copiers may be formed by uniformly partitioning the openings of one large horn copier. In this case, however, each opening is preferably connected to a signal processing unit including a low noise amplifier individually so as to form a separate horn copier.

  The sub-reflective plate 200 is disposed at the opening side of the horn copier 300 to reflect the radio waves from the horn copier 300 to the main reflector 100, or to transmit the radio waves from the main reflector 100 to the horn copier 300. To reflect. The sub reflector 200 is disposed at the focal position of the main reflector 100 so that the radio waves from the main reflector 100 are concentrated on the sub reflector 200 so that the central axis coincides with the main reflector 100. In addition, the sub-reflective plate 200 is formed to have a parabolic or hyperbolic cross section having a focus on the arrangement position of the horn copier 300 so that the radio waves are concentrated on the horn copier 300.

By the above configuration, as shown in FIG. 1, the radio wave W enters the main reflecting plate 100 in substantially parallel and is concentrated on the horn copier 300 through the sub reflecting plate 200. Therefore, even weak signals can be easily detected. The transmission of the signal is in the opposite path from the reception.

Next, specific signal transmission and reception in the antenna of the present embodiment will be described. 2 is a circuit diagram of a signal processing unit of a satellite tracking antenna according to an embodiment of the present invention. Each horn antenna 310, 320, 330, 340 of this embodiment is connected to a power divider 510-540 via a Low Noise Amplifier (LNA) 410-440 and the power divider 510-540 is a receiving terminal. R1-R4 and high-frequency phase shifters 610-640.

The high frequency phase shifters 610 to 640 are again connected to the control unit and the driving unit through the RF amplifiers 910 and 920, the mixer 1010, and the IF amplifier 1110. On the other hand, the receiving terminals R1 to R4 are sequentially connected to the receiving circuit via the LNAs 810 to 840, the RF amplifiers 930 and 940, the mixer 1020, and the IF amplifier 1120. On the other hand, the mixer 1020 is connected to the oscillator 1200 and mixes the oscillation signal with the received signal.

For example, the signal received by the antenna 310 is amplified by the LNA 410 and delivered to the power divider 510, where the power divider 510 is a high frequency phase shifter 510 and a receive terminal R1. To distribute the signal. The high frequency phase shifter 610 receives a monopulse wave by shifting the phase of the signal by a predetermined phase, preferably 90 degrees. At this time, the high frequency phase shifter 610 is capable of generating a monopulse wave including an RF switch.

In particular, the RF switch of the high frequency phase shifters 610 to 640 may be turned on / off by a TTL (Transistor-Transistor Logic) signal from a control unit, including a high frequency diode. As a result, the phase of the received signal from the antennas 310 to 340 is changed, and a monopulse wave is generated.

The monopulse wave is transmitted to the controller and driver through the RF amplifier 900, the mixer 1010, and the IF amplifier 1110, and the controller and the driver determine the position of the satellite based on the monopulse wave. Rotate to change its orientation. The driver may perform a change in orientation by transmitting a drive signal to the motor. On the other hand, the signal distributed to the receiving terminal R1 is sequentially passed through the LNA 800, the RF amplifier 900, the mixer 1020 and the IF amplifier 1120, and is delivered to the receiving circuit. The receiving circuit processes the transmitted signal to obtain necessary information. On the other hand, the transmission of the signal can be made in reverse to that described above.

As described above, the signal receiving circuit synchronized by the common oscillator and the monopulse wave generation circuit including the high frequency phase shifter may be integrally formed as one circuit or may be integrated into one component. It may also be included in the low noise block (NBN) of the antenna along with the down converter to simplify the configuration of the antenna.

As described above, the antenna of the present embodiment can perform both the generation of the mono pulse wave and the transmission and reception of data through one horn copier 310. Thus, the number of horn copiers 310 used can be reduced.

Next, the control method of the monopulse wave of this embodiment is demonstrated with reference to FIG. 3 is a plan view of a satellite tracking antenna according to an embodiment of the present invention. In the present embodiment, two or less horn copiers of four horn copiers 310, 320, 330, and 340 are selectively used to generate monopulse waves in various directions. Specifically, the position of the horn copier used and the generated monopulse wave is shown in Table 1 below.

As described above, the RF switch of the high frequency phase shifter may be turned on / off by a TTL (Transistor-Transistor Logic) signal from the control unit, and a predetermined horn copier is selected accordingly. Thereby, the phase of the received signal of the horn copiers 310, 320, 330, 340 is changed, and a monopulse wave is generated.

Selected horn copier Monopulse wave generation position BC1 (310) 10-11 o'clock BC2 (320) 1-2 o'clock BC3 (330) 4-5 o'clock BC4 (340) 7-8 o'clock

 BC: Beam Control Signal (TTL) (5V = ON / 0V = OFF)

In addition, referring to FIG. 4, the generation position of the monopulse wave according to each selected horn copier may be known in more detail.

In this way, by using a horn copier of 2 or less selectively and generating a monopulse wave at a specific position, it is possible to determine the position of the satellite by the monopulse method. The selection of the horn copier can be made quickly by the RF switch included in the high frequency phase shifter. Therefore, even when the sub reflector is fixedly arranged on the same axis as the main reflector, it is possible to generate monopulse waves in various directions and to perform positioning.

That is, the monopulse signal is changed by phase shifting the signal transmitted and received by the horn copier by switching the high frequency phase shifter at high speed, and the position of the satellite can be determined by the sum and difference calculation and / or the signal strength comparison between them. .

Therefore, according to the present embodiment, the mechanical configuration of the antenna can be simplified without requiring a separate component for the rotation of the sub reflector. In addition, monopulse waves can be generated without mechanical beam movement to reduce the scanning loss of the antenna and prevent signal degradation. In addition, since the monopulse wave is formed by the high frequency phase shifter independently separated by the power divider, the monopulse wave can be formed irrespective of the presence or absence of the sub-reflection plate, and can be easily applied to the parabola antenna.

5A and 5B illustrate an example of an antenna implemented by applying the principles of the above-described embodiment.

As shown in FIG. 5A, the antenna according to an embodiment of the present invention includes a main reflector 100, a sub-reflective plate 200, and a horn copier 300 divided into four compartments. As shown in FIG. 5B, the antenna according to the present invention includes a signal processor 520 for processing a signal received from the mixer 300 and a driver for displacing the antenna according to the position of the satellite determined by the signal processor 520. 540.

In addition, the principles of the above embodiments can be applied not only to antennas including horn radiators, but also to planar array antennas including a plurality of antenna elements. That is, by forming a planar antenna element instead of a horn copier, the position tracking antenna using a monopulse wave can be implemented as a planar array antenna by applying the principle of the above embodiment, and examples thereof are illustrated in FIGS. 6A and 6B. In particular, in FIG. 6B, the antenna includes a signal processor 600 and a driver 660 including an LNA 620, a phase shifter / down converter 640, and the like. In this case, unlike the previous embodiment, it is apparent to those skilled in the art that a reflector is not included.

While the present invention has been described above in connection with specific embodiments, this is only an example and the present invention is not limited thereto. Those skilled in the art can make various changes or modifications to the embodiments described based on this specification, which are also within the scope of the present invention. For example, the described embodiment has a Casegrain or Gregorian antenna configuration that includes a sub-reflective plate, but the principles of the present invention are equally applicable to any antenna configuration that uses a horn copier, such as a parabolic antenna. In addition, the various components described or illustrated as a simple functional block in the present invention may be composed of any known elements, integrated circuits, logic circuits, etc., and may be composed of a combination of two or more elements or integrated into one element. have. Therefore, the scope of the present invention should be defined not by the above description but by the appended claims and their equivalents.

1 is a perspective view of a satellite tracking antenna in accordance with an embodiment of the present invention.

2 is a circuit diagram of a signal processing unit of a satellite tracking antenna according to an embodiment of the present invention.

3 is a plan view of a satellite tracking antenna according to an embodiment of the present invention.

4 is a graph showing the positions of monopulse waves each generated by a horn copier according to one embodiment of the present invention;

5A and 5B are perspective views of a satellite tracking antenna device implemented in accordance with one embodiment of the present invention.

6A and 6B are perspective views of a satellite tracking antenna device implemented in accordance with another embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

100: main reflection plate

200: Sub-Judge Judge

300: Horn Copier

Claims (10)

At least one antenna element for transmitting and receiving radio waves; A low noise amplifier connected to each of the antenna elements; And A high frequency phase shifter connected to said low noise amplifier, And the antenna element generates a monopulse wave by the low noise amplifier and the high frequency phase shifter. The method of claim 1, The satellite tracking antenna has a parabolic cross section for reflecting radio waves. Further includes a reflector, And the antenna element is a horn copier. The method of claim 2, The at least one horn copier is formed by partitioning the opening of one horn copier, Satellite tracking antenna. The method of claim 2, A sub-reflective plate that reflects radio waves from the horn copier to the reflecting plate, And further comprising a sub-reflective plate disposed on the same axis as the reflector. antenna. The method of claim 1, The antenna element is connected to a low noise amplifier and the low noise amplifier is powered Connected to the distributor, The power divider includes a signal receiving circuit and a signal from the antenna element. Satellite tracking antenna, distributed with a high frequency phase shifter. The method of claim 5, wherein The signal distributed by the power divider is synchronized by a common oscillator, and the signal receiving circuit and the high frequency phase shifter are included in one low noise block (LNB). The method of claim 1, The high frequency phase shifter includes an RF (Radio Freqeuncy) switch, 2 or less antenna elements of the antenna elements are selectively used through switching of the RF switch. The method of claim 1, And a driver for displacing the antenna according to the position of the satellite determined based on the generation of the monopulse wave. The method of claim 1, The antenna comprises four antenna elements, And the antenna elements are arranged in a 2 × 2 matrix form. At least one antenna element for transmitting and receiving radio waves, and said antenna element being mono A position tracking method using a satellite tracking antenna comprising a high frequency phase shifter connected to each said antenna element to generate a pulse wave, And positioning the satellites selectively using two or less of the antenna elements.

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