CN212086200U

CN212086200U - High-speed self-adaptive space laser communication receiver structure

Info

Publication number: CN212086200U
Application number: CN202020501206.3U
Authority: CN
Inventors: 肖创易
Original assignee: Nanjing Aerospace Communications Technology Co ltd
Current assignee: Nanjing Aerospace Communications Technology Co ltd
Priority date: 2020-04-08
Filing date: 2020-04-08
Publication date: 2020-12-04
Anticipated expiration: 2030-04-08

Abstract

The utility model discloses a high-speed self-adaptation space laser communication receiver structure, including the satellite main part, install signal antenna in the satellite main part, the radar main part is installed to signal antenna's lower extreme, communication receiver is installed to the front end of satellite main part, is provided with QD photoelectric converter on the communication receiver, through electric connection between QD photoelectric converter's the output and weak signal of telecommunication amplifier's the input, through electric connection between weak signal of telecommunication amplifier's the output and equalizer filter's the input, through electric connection between equalizer filter's the output and the input of AD sampling converter, through electric connection between AD sampling converter's the output and the input of AD input buffer. The utility model discloses except AD sampling chip input frequency's self-adaptation function innovation, still have the characteristics of high bandwidth low noise to DDS + PLL's mixed frequency synthesis scheme can provide stable and accurate high frequency clock for the AD chip.

Description

High-speed self-adaptive space laser communication receiver structure

Technical Field

The utility model relates to a satellite communication technical field specifically is a high-speed self-adaptation space laser communication receiver structure.

Background

With the increasing number of satellites outside the atmosphere and the decreasing number of available wireless communication bands, the space laser communication technology has been paid more and more attention from various countries in recent years. Although space laser communication is not limited by some physical factors such as atmospheric turbulence, dispersion and the like of atmospheric laser communication, a high background noise field exists, and meanwhile, due to long-distance laser signal transmission, the power of a laser signal captured at a receiving end is extremely low, and meanwhile, strong noise interference exists. The optical receiver is an indispensable part of a laser communication system, and can convert a weak optical signal in a channel into a digital electrical signal which is convenient to process for subsequent circuits. The invention provides a brand-new high-speed self-adaptive space laser communication receiver structure, which consists of QD, a preamplification circuit, an AD sampling conversion circuit and a digital STR phase discriminator.

In order to make the signal processing process simpler and more efficient, the analog electrical signal is converted into a digital electrical signal through an AD sampling analog-to-digital conversion circuit in the design process. The general optical receiver only carries out the process of amplifying the analog electric signal, the following process is realized by other parts, the AD sampling process has no comprehensive technical requirements and complete sampling process control, and the following series of signal processing operations can be influenced to a certain extent, particularly in the aspect of signal processing speed, so that the market urgently needs to develop a novel high-speed self-adaptive space laser communication receiver structure.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a high-speed self-adaptation space laser communication receiver structure to solve the problem that proposes among the above-mentioned background art.

In order to achieve the above object, the utility model provides a following technical scheme: the utility model provides a high-speed self-adaptation space laser communication receiver structure, includes the satellite main part, install signal antenna in the satellite main part, the radar main part is installed to signal antenna's lower extreme, communication receiver is installed to the front end of satellite main part, is provided with QD photoelectric converter on the communication receiver, through electric connection between QD photoelectric converter's the output and the input of weak signal of telecommunication amplifier, through electric connection between the output of weak signal of telecommunication amplifier and equalizer filter's the input, through electric connection between equalizer filter's the output and the input of AD sampling converter, through electric connection between AD sampling converter's the output and the input of AD input buffer.

Preferably, a signal receiver is installed below the communication receiver.

Preferably, the output end of the AD input buffer is electrically connected to the input end of the STR phase detector.

Preferably, the output terminal of the STR phase detector is electrically connected to the input terminal of the STR loop filter.

Preferably, the STR loop filter is electrically connected to the input terminal of the direct digital frequency synthesizer through the DDS controller.

Preferably, the output end of the direct digital frequency synthesizer is electrically connected with the input end of the AD input buffer.

Compared with the prior art, the beneficial effects of the utility model are that:

in order to realize the self-adaptive design of the AD sampling rate, the utility model adopts the DDS + PLL mode to generate the signal frequency needed by the AD chip, the mixed frequency synthesis mode combines the advantages of the DDS and the PLL in the process of generating frequency respectively, so that the DDS and the PLL have the capability of rapidly jumping frequency in the process of outputting high-frequency signals, an STR phase discriminator is added behind the AD chip, the phase discriminator can compare the feedback of the generated signal with the input signal, the change of the signal frequency is obtained through the comparison of the two, thereby generating a signal to control the step of the DDS, thereby achieving the purpose of changing the frequency, having the characteristics of high bandwidth and low noise besides the self-adaptive function innovation of the input frequency of the AD sampling chip, and the mixed frequency synthesis scheme of the DDS + PLL can provide a stable and accurate high frequency clock to the AD chip.

Drawings

Fig. 1 is a schematic structural diagram of a satellite main body of the present invention;

fig. 2 is a front view of the satellite main body of the present invention;

fig. 3 is a schematic block diagram of the present invention.

In the figure: 1. a radar main body; 2. a signal antenna; 3. a satellite body; 4. a communication receiver; 5. a QD photoelectric converter; 6. a signal receiver; 7. an equalization filter; 8. an AD input buffer; 9. an STR phase discriminator; 10. an STR loop filter; 11. a weak electrical signal amplifier; 12. an AD sampling converter; 13. a direct digital frequency synthesizer; 14. a DDS controller.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments.

Referring to fig. 1-3, the present invention provides an embodiment: the utility model provides a high-speed self-adaptation space laser communication receiver structure, including satellite main body 3, install signal antenna 2 on the satellite main body 3, radar main body 1 is installed to signal antenna 2's lower extreme, communication receiver 4 is installed to satellite main body 3's front end, be provided with QD photoelectric converter 5 on the communication receiver 4, pass through electric connection between QD photoelectric converter 5's the output and the input of weak signal of telecommunication amplifier 11, pass through electric connection between the output of weak signal of telecommunication amplifier 11 and the input of equalizer filter 7, pass through electric connection between the output of equalizer filter 7 and the input of AD sampling converter 12, pass through electric connection between the output of AD sampling converter 12 and the input of AD input buffer 8.

Further, a signal receiver 6 is installed below the communication receiver 4.

Further, the output end of the AD input buffer 8 is electrically connected to the input end of the STR phase detector 9.

Further, the output terminal of the STR phase detector 9 is electrically connected to the input terminal of the STR loop filter 10.

Further, the STR loop filter 10 is electrically connected to the input terminal of the direct digital frequency synthesizer 13 through the DDS controller 14.

Further, the output terminal of the direct digital frequency synthesizer 13 is electrically connected to the input terminal of the AD input buffer 8.

The working principle is as follows: when the device is used, a communication receiver 4 is installed at the front end of a satellite main body 3, a QD photoelectric converter 5 is arranged on the communication receiver 4, in order to meet the requirement of the overall structure of the receiver, the QD photoelectric converter 5 is used as a photoelectric conversion element at the front end of the receiver, the QD photoelectric converter 5 is an element with a position indication function formed by combining 4 APDs in an array mode, and is a necessary core element for realizing space laser communication, in the space laser communication, the transmission distance of a beam of laser is very long, the receiver is required to have a quick and accurate capturing, tracking and aiming technology, the QD photoelectric converter 5 is the key for realizing the technology, and in the aspect of weak signal receiving, the high sensitivity of QDs can also enable NWs and even PW-level weak laser signals to be received; but in order to control the volume and quality of the optical receiver to be very small, abandon the use of a narrow band optical filter on an optical channel, which can effectively inhibit the interference of background stray light on the received optical signal, the output end of the QD photoelectric converter 5 is electrically connected with the input end of the weak electrical signal amplifier 11, the electrical signal converted by the QD photoelectric converter 5 is very weak, the weak electrical signal is very difficult to process, the signal extraction and integrity can be seriously influenced by the null shift, noise and channel transmission of common operational amplifiers, so the optical receiver adopts a three-level amplification filter circuit, and simultaneously adopts an optical weak isolator to isolate communication, thereby improving the anti-interference capability of the electrical signal, the weak electrical signal amplification filter circuit has simple structure, low cost and easy realization, the output end of the weak electrical signal amplifier 11 is electrically connected with the input end of the equalizing filter 7, the output end of the equalizing filter 7 is electrically connected with the input end of the AD sampling converter 12, the AD sampling converter 12 converts the amplified and filtered analog electric signal into a digital electric signal, so as to facilitate the subsequent digital signal processing process, the speed of the AD sampling converter 12 determines the speed of the whole system, a DDS + PLL scheme is adopted to provide an accurate and stable clock for an AD chip, and a Phase-Locked frequency synthesis technology formed by a Phase-Locked loop (PLL) has the advantages of extremely wide frequency range, good spurious suppression performance, high output spectrum purity and easy program control of output frequency, but the main defect of the Phase-Locked frequency synthesis technology is that the frequency conversion time is long, so that the fast frequency hopping is difficult to realize, and the Phase noise of the output spectrum is deteriorated when the frequency resolution is low; the direct digital frequency synthesis technology has extremely fast high-speed frequency hopping capability, high frequency and phase resolution capability, but has a lot of defects in bandwidth and spectral purity, PLL and DDS are combined together, the two make up for the deficiency are a very reasonable frequency synthesis solution, in the conversion process of the AD sampling converter 12, an LVDS interface is adopted during the signal transmission of an AD chip, so that the signal can be transmitted on a differential PCB line and a pair of balanced cables at the maximum speed of hundreds of Mbits/s, and because LVDS adopts a low-voltage and low-current driving mode, the LVDS is a low-noise and low-power transmission mode, the output end of the AD sampling converter 12 is electrically connected with the input end of the AD input buffer 8, the output end of the AD input buffer 8 is electrically connected with the input end of the STR phase discriminator 9, by sending the digital signal STR converted by the AD sampling converter 12 to the phase discriminator 9, the phase discriminator is also called as a phase comparator, which is a circuit that the phase difference between input signals and feedback signals has a definite relation with the output voltage, a signal for step control of DDS is generated through the difference between the two, so as to adjust the speed of the AD sampling rate, a counter with controllable depth adjustment exists in the process, when the phase discriminator generates the DDS step control signal, the counter can carry out addition or subtraction operation according to the situation, the output end of the STR phase discriminator 9 is electrically connected with the input end of the STR loop filter 10, the loop filter is called as a filter, because the circuit has the following two functions: the phase error that high frequency component and input signal noise that the decay phase detector sent arouse, so loop filter generally makes by loop filter's rank and the bandwidth decision of noise to the dynamic response of signal, the utility model provides a high-speed self-adaptation space laser communication receiver structure comprises above 5 parts, except the self-adaptation function innovation of AD sampling chip input frequency, still has the characteristics of high bandwidth low noise to DDS + PLL's mixed frequency synthesis scheme can provide stable and accurate high frequency clock for the AD chip.

It is obvious to a person skilled in the art that the invention is not restricted to details of the above-described exemplary embodiments, but that it can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Claims

1. A high-speed adaptive space laser communication receiver structure comprises a satellite main body (3), it is characterized in that the satellite main body (3) is provided with a signal antenna (2), the lower end of the signal antenna (2) is provided with a radar main body (1), a communication receiver (4) is arranged at the front end of the satellite main body (3), a QD photoelectric converter (5) is arranged on the communication receiver (4), the output end of the QD photoelectric converter (5) is electrically connected with the input end of the weak electric signal amplifier (11), the output end of the weak electric signal amplifier (11) is electrically connected with the input end of the equalizing filter (7), the output end of the equalizing filter (7) is electrically connected with the input end of the AD sampling converter (12), and the output end of the AD sampling converter (12) is electrically connected with the input end of the AD input buffer (8).

2. The high speed adaptive spatial laser communication receiver architecture of claim 1, wherein: and a signal receiver (6) is arranged below the communication receiver (4).

3. The high speed adaptive spatial laser communication receiver architecture of claim 1, wherein: the output end of the AD input buffer (8) is electrically connected with the input end of the STR phase discriminator (9).

4. A high speed adaptive spatial laser communication receiver architecture as claimed in claim 3, wherein: the output end of the STR phase detector (9) is electrically connected with the input end of the STR loop filter (10).

5. The high speed adaptive spatial laser communication receiver architecture of claim 4, wherein: the STR loop filter (10) is electrically connected with the input end of the direct digital frequency synthesizer (13) through the DDS controller (14).

6. The high speed adaptive spatial laser communication receiver architecture of claim 5, wherein: the output end of the direct digital frequency synthesizer (13) is electrically connected with the input end of the AD input buffer (8).