Satellite communication antenna and signal transmission method applicable to high and low orbit satellites

Abstract

Applicable to airborne satellite communication antennas and signal transmission methods for high and low orbit satellites, and relate to the field of airborne satellite communication antennas. It includes a transmitting and receiving channel component, and the transmitting and receiving channel component includes an antenna array, a limiter, a low noise amplifier, a phase shifter, a 90° bridge, a switch, a power divider, and an amplitude modulator / phase shifter connected in sequence. The amplitude modulator / phase shifter is connected to a power division network, and the power division network includes a multi-channel power divider, a frequency selective filter, a phase shifter, and a combined power divider connected in sequence. After the signal passes through the multi-channel power divider, the original signal is divided into multiple signals, and then passes through frequency selective filters, phase shifters, and combined power dividers of different frequency bands to generate two different signals with frequencies f0 and f1. After down-conversion by a frequency source, two different signals are output. The present invention can realize that the satellite communication antenna receives two signals at the same time, supports large-capacity data transmission, and solves the problem that the high-orbit satellite communication antenna is not directly compatible with low-orbit satellite communication.

Description

Technical Field

[0001] The present invention relates to the technical field of airborne satellite communication-phased array satellite communication antennas, and in particular to an airborne satellite communication antenna suitable for high and low orbit satellites and a signal transmission method. Background Art

[0002] Satellite communication refers to a communication method that uses satellites as relay stations to transmit or forward radio waves. It has the characteristics of wide coverage, long communication distance, wide communication frequency band, and no terrain or geographical restrictions. It is divided into geosynchronous orbit, medium orbit, low orbit, etc. according to the satellite orbit.

[0003] The advantage of geostationary orbit (GEO) communication satellites is that only three satellites are needed to cover the entire world except the two poles, and they have become an important tool for global intercontinental telecommunications. Compared with GEO satellite communication systems, low-orbit (LEO) satellite communications orbit the earth in a relatively low orbit, with advantages such as low transmission loss, short transmission delay, and flexible satellite launch, and can achieve global coverage including the North and South Poles through constellation networking.

[0004] The orbital altitude of low-orbit satellite communications is about 1 / 30 of the orbital altitude of GEO, and has the advantages of low signal free space loss, small propagation delay, and low ground multipath fading. However, in order to achieve global coverage, orbital satellites need to use a large number of satellites, and the satellites move at high speed relative to the earth's surface. Satellite communications need to switch between different satellites, and satellite communication equipment needs to have variable polarization and fast satellite alignment capabilities. The orbital satellite system has a high communication capacity, requiring satellite antennas to have higher data capacity transmission capabilities.

[0005] As an important part of the new infrastructure, low-orbit satellite communications are in a stage of rapid development in China and are bound to be an important development direction for satellite communications. Currently, most of the high-orbit satellite communication antennas on the market are mature applications. At the beginning of the design of these high-orbit satellite communication antennas, due to the limitations of communication frequency bands and application scenarios, the working frequency bands of the antennas are generally fixed and narrow-band antennas, and some antennas are directional antennas that cannot change direction as needed. They can only receive signals at a single frequency and are not directly applicable to low-orbit satellite communications. In addition, the antenna G / T value required for low-orbit communications is smaller than that for high-orbit communications.

[0006] Since the beamforming component design of existing airborne satellite communication antennas has only one output, the existing high-orbit satellite communication antennas only support communications with the satellite with the strongest current received signal amplitude, that is, they only communicate with one satellite and do not support the communication needs of low-orbit satellite communications.

[0007] Based on the above background, based on the needs of low-orbit satellite communication antennas and combined with the design concept of high-orbit satellite communication antennas, an airborne satellite communication antenna suitable for high-orbit and low-orbit satellites was designed. The antenna has a wide bandwidth, supports large-capacity data transmission, has variable polarization, supports multi-frequency reception and rapid satellite alignment. Summary of the invention

[0008] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides an airborne satellite communication antenna and signal transmission method suitable for high and low orbit satellites, and an airborne active phased array satellite communication antenna suitable for low orbit satellites, which meet the requirements of low orbit satellite communication for wide bandwidth, support for large-capacity data transmission, variable polarization mode and rapid satellite alignment.

[0009] In order to achieve the above object, the main technical solutions adopted by the present invention include:

[0010] The invention is suitable for airborne satellite communication antennas of high and low orbit satellites, and comprises a transmitting and receiving channel component, wherein the transmitting and receiving channel component comprises an antenna array, a limiter, a low noise amplifier, a phase shifter, a 90° bridge, a switch, a power divider, and an amplitude modulator / phase shifter connected in sequence, wherein the amplitude modulator / phase shifter is connected to a power division network, and the power division network comprises a multi-channel power divider, a frequency selective filter, a phase shifter, and a combining power divider connected in sequence. After the signal passes through the multi-channel power divider, the original signal is divided into multiple signals, and then passes through frequency selective filters, phase shifters, and combining power dividers of different frequency bands to generate two different signals with frequency points of f0 and f1, which are down-converted by a frequency source and output to obtain two different signals.

[0011] Furthermore, the antenna array includes a plurality of antenna units, which are broadband dual circularly polarized microstrip antennas combining an air layer and a dielectric layer. The input end of a single receiving channel of the antenna's radiating array includes a group of vertical polarization ports and a group of horizontal polarization ports. The vertical polarization signals and horizontal polarization signals output by the radiating units are first amplified by a low-noise amplifier, and then the phase of the received signal is adjusted by a phase modulator. The left-hand polarization or right-hand polarization signal synthesis is achieved through a 90° bridge, and the left / right-hand polarization is determined according to a control command.

[0012] Furthermore, the antenna unit realizes a 90° phase shift feeding system through a post-stage phase shifter of the radiation array.

[0013] Furthermore, the antenna adopts a laminated microstrip antenna structure, multi-point eccentric feeding combined with a power division circuit.

[0014] Furthermore, the dielectric constant of the dielectric plate of the antenna unit is 3.3.

[0015] Furthermore, the antenna units and the unit spacing meet the conditions of satisfying the designed gain bandwidth, minimizing the standing wave and maximizing the unit gain, and the radiation units are obtained through array layout.

[0016] The signal transmission method using the antenna comprises the following steps:

[0017] S01: The vertical polarization signal and horizontal polarization signal output by the radiation unit are first amplified by a low noise amplifier, and then the phase of the received signal is adjusted by a phase modulator, and the left-hand polarization or right-hand polarization signal is synthesized by a 90° bridge, and the left / right polarization is determined according to the control command;

[0018] S02: The high-frequency signal obtained by the transmitting / receiving channel component is f. Each signal is divided into two identical signals by a power divider. The two signals are filtered by different frequency selective filters respectively. After the phase is adjusted by the phase shifter and the amplitude is modulated by the attenuator, signals of different frequencies f0 and f1 are obtained.

[0019] S03: All channels with output f0 are subjected to signal beam synthesis and down-converted by the frequency source to obtain a signal with frequency point F0; all channels with output f1 are subjected to signal beam synthesis and down-converted by the frequency source to obtain a signal with frequency point F1.

[0020] The beneficial effects of the present invention are:

[0021] The present invention adopts a laminated microstrip antenna structure, multi-point eccentric feeding combined with a power division circuit. By adding a power divider and an additional doubled phase shift and attenuation circuit to the old beam synthesis component, and then passing through different frequency-selective filters, it realizes the function of screening out two different satellite signals from the received satellite signal, forming a phased array antenna that supports low-orbit and high-orbit satellite communications. While widening the antenna working bandwidth, the antenna channel capacity is increased, and the variable polarization mode function of the airborne satellite communication antenna is realized, supporting different satellite communication functions. Using the phased array antenna system as the basis, the antenna beam pointing can be agilely changed, and it has the rapid satellite alignment capability required to support low-orbit communications. The present invention realizes the expansion of the receiving channel, while supporting at least two-way reception, and realizing the data expansion function. By optimizing the design of antenna array element gain, increasing the number of array elements, and improving the G / T value required for high-orbit satellite communications, the antenna has the same high-orbit satellite communication capability requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the beam synthesis principle of the airborne satellite communication antenna of the present invention;

[0023] Figure 2 A schematic diagram of a feeding point of an antenna unit of the present invention;

[0024] Figure 3 It is a schematic diagram of the structure of the antenna unit of the present invention;

[0025] Figure 4 It is a schematic diagram of the variable polarization principle of the present invention;

[0026] Figure 5 It is a schematic diagram of the principle of the multi-channel receiving channel of the present invention. DETAILED DESCRIPTION

[0027] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0028] The present invention provides a satellite communication antenna suitable for high and low orbit satellites, such as Figure 1 As shown, it includes a transmitting and receiving channel component, which includes an antenna array, a limiter, a low noise amplifier, a phase shifter, a 90° bridge, a switch, a power divider, and an amplitude modulator / phase shifter connected in sequence. The amplitude modulator / phase shifter is connected to a power division network, and the power division network includes a multi-channel power divider, a frequency selective filter, a phase shifter, and a combined power divider connected in sequence. After the signal passes through the multi-channel power divider, the original signal is divided into multiple signals, and then passes through frequency selective filters, phase shifters, and combined power dividers of different frequency bands to generate two different signals with frequencies f0 and f1. After down-conversion by a frequency source, two different signals are output.

[0029] The antenna array of the present invention includes a plurality of antenna units, such as Figure 2-3 As shown, the antenna unit is a broadband dual circular polarization microstrip antenna in the form of an air layer and a dielectric layer. The antenna unit adopts a dual-feed point excitation circular polarization form, and the 90° phase shift feeding system is realized by the radiation array post-stage phase shifter. The left and right circular polarizations are realized by the 90° phase difference of the two mutually perpendicular lines. Figure 4 As shown, the input end of a single receiving channel of the antenna's radiating array includes a set of vertical polarization ports and a set of horizontal polarization ports. The vertical polarization signal and horizontal polarization signal output by the radiating unit are first amplified by a low noise amplifier, and then the phase of the received signal is adjusted by a phase modulator. The left-hand polarization or right-hand polarization signal synthesis is realized through a 90° bridge, and the left / right-hand polarization is determined according to the control command, thereby realizing variable signal polarization. The antenna unit realizes a 90° phase shift feeding system through the post-stage phase shifter of the radiating array. The antenna adopts a laminated microstrip antenna structure, multi-point eccentric feeding combined with a power division circuit to realize the variable polarization mode function of the airborne satellite communication antenna, and supports different satellite communication functions.

[0030] The present invention selects a dielectric plate with a dielectric constant of 3.3 to design an antenna unit. The antenna unit and the unit spacing meet the conditions of minimum standing wave and maximum unit gain under the conditions of satisfying the designed gain bandwidth, and a radiation unit is obtained through array layout.

[0031] Multiple receiving channels realize large-capacity design:

[0032] like Figure 5As shown in the figure, the vertical polarization signal and the horizontal polarization signal output by the radiating unit are first amplified by a low noise amplifier, and then the beam direction is controlled by a phase modulator. The left-hand polarization or right-hand polarization signal synthesis is realized by a 90-degree bridge. The formed left-hand / right-hand signal is divided into two identical signals by a power divider. After different phase shifts and attenuations, the previous same carrier signal is divided into carrier signals of different frequencies, which are synthesized by power dividers respectively, and finally multiple beam signals of different frequencies are output. Figure 5 This is a schematic diagram of two different frequency beam signals, which realizes the function of increasing receiving channels and receiving signals of different frequencies, and realizes large-capacity design. The satellite communication antenna increases the receiving channel to realize the data expansion function.

[0033] The radiation unit receives electromagnetic waves, amplifies the vertical and horizontal polarization signals through a low-noise amplifier, adjusts the phase through a digital phase shifter, and then combines them through a 90° bridge to synthesize circularly polarized signals. At this stage, left-handed or right-handed circular polarization is adjusted by the 90° phase of the switch-controlled bridge. The electrical signal at this time is divided into two by a power divider to form two signals with the same amplitude and phase. The two information is subjected to different phase shifting, attenuation, filtering and low-noise amplification to form two useful signals with different frequencies. The same-frequency signals obtained by multiple radiation units through the above process are beamformed to obtain the final two useful signals with different frequencies.

[0034] The present invention also provides a signal transmission method using the antenna, comprising the following steps:

[0035] S01: The vertical polarization signal and horizontal polarization signal output by the radiation unit are first amplified by a low noise amplifier, and then the phase of the received signal is adjusted by a phase modulator, and the left-hand polarization or right-hand polarization signal is synthesized by a 90° bridge, and the left / right polarization is determined according to the control command;

[0036] S02: The high-frequency signal obtained by the transmitting / receiving channel component is f. Each signal is divided into two identical signals by a power divider. The two signals are filtered by different frequency selective filters respectively. After the phase is adjusted by the phase shifter and the amplitude is modulated by the attenuator, signals of different frequencies f0 and f1 are obtained.

[0037] S03: All channels with output f0 are subjected to signal beam synthesis and down-converted by the frequency source to obtain a signal with frequency point F0; all channels with output f1 are subjected to signal beam synthesis and down-converted by the frequency source to obtain a signal with frequency point F1.

[0038] The antenna receives an electromagnetic wave signal with a frequency of f. The bandwidth of f includes f0 and f1, that is, the antenna supports the reception of two electromagnetic wave signals with different frequencies at the same time.

[0039] Combining the above steps, the reception of dual-frequency signals is achieved through the design of multi-channel receiving channels. While broadening the antenna working bandwidth, the antenna channel capacity is increased, and it has the large-capacity data transmission capability required to support low-orbit communications. It uses a phased array antenna system as the basis, which can achieve agile antenna beam pointing and has the rapid satellite alignment capability required to support low-orbit communications.

[0040] By optimizing the design of antenna element gain, increasing the number of elements and improving the G / T value required for high-orbit satellite communications, the antenna can have the same high-orbit satellite communication capabilities.

[0041] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. Alterations, modifications, substitutions and variations of the above embodiments by a person skilled in the art are all within the scope of the present invention.

Claims

1. Suitable for satellite communication antennas on high and low orbit satellites, including a transmitting and receiving channel component, wherein the transmitting and receiving channel component includes an antenna array, a limiter, a low noise amplifier, a phase shifter, a 90° bridge, a switch, a power divider, and an amplitude modulation / phase shifter connected in sequence, characterized in that: The amplitude modulator / phase shifter is connected to a power division network, and the power division network includes a multi-channel power divider, a frequency selective filter, a phase shifter, and a combined power divider connected in sequence. After the signal passes through the multi-channel power divider, the original signal is divided into multiple signals, and then passes through frequency selective filters, phase shifters, and combined power dividers of different frequency bands to generate two different signals with frequencies f0 and f1. After down-conversion by a frequency source, two different signals are output; the antenna array surface includes a plurality of antenna units, and the antenna unit is a broadband dual circularly polarized microstrip antenna combining an air layer and a dielectric layer. The input end of a single receiving channel of the antenna's radiation array includes a group of vertical polarization ports and a group of horizontal polarization ports. The vertical polarization signal and the horizontal polarization signal output by the radiation unit are first amplified by a low noise amplifier, and then the phase of the received signal is adjusted by a phase modulator. The left-hand polarization or right-hand polarization signal synthesis is realized by a 90° bridge, and the left / right-hand polarization is determined according to a control command.

2. The satellite communication antenna suitable for high and low orbit satellites according to claim 1, characterized in that: The antenna unit realizes a 90° phase shift feeding system through a radiation array post-stage phase shifter.

3. The satellite communication antenna suitable for high and low orbit satellites according to claim 1, characterized in that: The antenna adopts a laminated microstrip antenna structure, multi-point eccentric feeding and a power division circuit.

4. The satellite communication antenna suitable for high and low orbit satellites according to claim 1, characterized in that: The dielectric constant of the dielectric plate of the antenna unit is 3.

3.

5. The satellite communication antenna suitable for high and low orbit satellites according to claim 1, characterized in that: The antenna units and unit spacing meet the conditions of satisfying the designed gain bandwidth, minimizing the standing wave and maximizing the unit gain, and the radiation units are obtained through array layout.

6. A signal transmission method using the antenna according to any one of claims 1 to 5, characterized in that: The steps include: S01: The vertical polarization signal and horizontal polarization signal output by the radiation unit are first amplified by a low noise amplifier, and then the phase of the received signal is adjusted by a phase modulator, and the left-hand polarization or right-hand polarization signal is synthesized by a 90° bridge, and the left / right polarization is determined according to the control command; S02: The high-frequency signal obtained by the transmitting / receiving channel component is f. Each signal is divided into two identical signals by a power divider. The two signals are filtered by different frequency selective filters respectively. After the phase is adjusted by the phase shifter and the amplitude is modulated by the attenuator, signals of different frequencies f0 and f1 are obtained. S03 performs signal beam synthesis on all channels that output f0 and down-converts the frequency source to obtain a signal with a frequency point of F0; All channels that output f1 perform signal beam synthesis and down-convert through a frequency source to obtain a signal with a frequency point of F1.

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