CN217985079U

CN217985079U - UHF frequency band satellite communication simulation transponder

Info

Publication number: CN217985079U
Application number: CN202221792183.1U
Authority: CN
Inventors: 张家勋; 姚卫刚
Original assignee: China North Communication Technology Co ltd
Current assignee: China North Communication Technology Co ltd
Priority date: 2022-07-09
Filing date: 2022-07-09
Publication date: 2022-12-06
Anticipated expiration: 2032-07-09

Abstract

The utility model relates to a UHF frequency channel satellite communication simulation transponder, it contains following component parts: the duplexer realizes the isolation of receiving and transmitting and enables the receiving and transmitting to work simultaneously without mutual interference; the low-noise amplifier amplifies weak received signals, and improves the signal-to-noise ratio of the received signals; the frequency mixer and the 45MHz constant-temperature crystal oscillator complete the frequency conversion of the radio-frequency signals; the band-pass filter filters out the out-of-band signal and allows the in-band signal to pass through; the pi-type attenuator and the adjustable attenuator are matched to complete receiving and generating level matching, the key point is receiving and generating level matching, the UHF frequency band satellite communication equipment can communicate without occupying satellite resources, the overhaul or troubleshooting of the UHF frequency band satellite communication equipment is realized, and particularly the flight inspection, troubleshooting or fixed inspection of the UHF frequency band satellite communication airborne station is realized.

Description

UHF frequency band satellite communication simulation transponder

Technical Field

The utility model belongs to UHF frequency channel satellite communication field mainly relates to under the condition that does not occupy the satellite resource, realizes carrying out the simulation repeater and the realization circuit that maintain the detection to UHF frequency channel satellite communication equipment.

Background

When satellite communication is carried out, signals are received and transmitted through a transponder on the satellite, and the satellite communication resources are released when the communication is completed.

However, satellite communication resources are limited, in actual satellite communication, the satellite communication resources are distributed as required, the satellite communication resources are released when the communication is completed, and when a satellite communication carrier station on an airplane is subjected to flight inspection, regular maintenance and troubleshooting, outfield detection equipment is required to be communicated with the satellite communication carrier station, but scarce satellite resources cannot be occupied, so that it is necessary to design a simulation transponder to replace a transponder on a satellite to meet the requirements of actual application.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to design a transponder and realization circuit on UHF frequency channel satellite communication simulation transponder substitution satellite.

The utility model provides a following technical scheme: an UHF band satellite communication analog transponder comprising: the duplexer realizes the isolation of receiving and transmitting and enables the receiving and transmitting to work simultaneously without mutual interference; the low-noise amplifier amplifies weak received signals, and improves the signal-to-noise ratio of the received signals; the frequency mixer and the 45MHz constant temperature crystal oscillator complete the frequency conversion of the radio frequency signal; the band-pass filter filters out the out-of-band signal and allows the in-band signal to pass through; the pi-type attenuator and the adjustable attenuator are matched to complete the matching of receiving and generating levels.

Further, a signal from the external field detection equipment enters the pi-type attenuator 1 through the duplexer 1, the signal enters the (392.5 +/-3.5) MHz band-pass filter for filtering after being subjected to proper attenuation and matching, the filtered signal and a signal from the 45MHz constant-temperature crystal oscillator enter the mixer 1 for mixing, and a radio-frequency signal after mixing enters an antenna through the duplexer 2 and is emitted through the antenna to be used as a receiving signal of the airborne station.

Furthermore, a received signal from an antenna enters the pi-type attenuator 2 through the duplexer 2, the signal enters the low-noise amplifier after being properly attenuated and matched, the amplified received signal and a signal from the 45MHz constant-temperature crystal oscillator enter the mixer 2 for mixing, the mixed received signal enters a (347.5 +/-3.5) MHz band-pass filter for filtering, and the filtered received signal enters the external field detection equipment through the duplexer 1 to serve as a received signal of the external field detection equipment.

Furthermore, a combined scheme of a duplexer and a band-pass filter is adopted, so that the receiver and the transmitting signal share one antenna, and the simultaneous operation of receiving and transmitting without mutual interference is realized.

Further, when amplifying a weak signal, the noise of the amplifier itself seriously interferes with the signal, so it is desirable to reduce the noise to improve the signal-to-noise ratio of the output, and the low noise amplifier is an amplifier with a very low noise coefficient, so the low noise amplifier is adopted at the receiving end for amplification.

Furthermore, the receiving frequency range of UHF frequency band satellite communication is (344-351) MHz, so that the receiving signal is filtered by a (347.5 +/-3.5) MHz band-pass filter, out-of-band signals are filtered, and in-band signals are passed.

Furthermore, the UHF frequency band satellite communication transmission frequency range is (389-396) MHz, so that the transmission channel adopts a (392.5 +/-3.5) MHz band-pass filter for filtering, out-of-band signals are filtered, and in-band signals pass through.

Furthermore, the maintenance, the inspection or the fault elimination of the UHF frequency band satellite communication equipment by the external field detection equipment can be realized under the condition that satellite resources are not occupied.

The realization circuit of the analog repeater mainly comprises: duplexer (two), pi-type attenuator (two), mixer (two), low noise amplifier, (392.5 + -3.5) MHz band-pass filter, (347.5 + -3.5) MHz band-pass filter and 45MHz constant temperature crystal oscillator. The duplexer, (392.5 +/-3.5) MHz band-pass filter and (347.5 +/-3.5) MHz band-pass filter share one antenna for receiving and sending signals in the analog repeater, so that the simultaneous operation of receiving and sending without mutual interference is realized; the pi-type attenuator is used for signal attenuation and realizes level matching; the low-noise amplifier amplifies the radio frequency signals in the receiving frequency band, and improves the signal-to-noise ratio of the received signals; the mixer and the 45MHz constant temperature crystal oscillator complete frequency conversion of radio frequency signals, realize frequency conversion that the frequency of the output radio frequency signal is 45MHz lower than that of the input radio frequency signal, the analog repeater has two external interfaces of a host interface and an antenna interface, and the host interface is connected to the external field detection equipment through a radio frequency cable; the antenna port is connected with a UHF frequency band satellite communication antenna. Therefore, the communication between the outfield detection equipment and the onboard station can be realized under the condition of not occupying satellite resources, and the outfield detection of the onboard station is finished.

The technical characteristics of the utility model are that:

the signal from the external field detection equipment enters a pi-type attenuator 1 through a duplexer 1, the signal enters a (392.5 +/-3.5) MHz band-pass filter for filtering after being properly attenuated and matched, the filtered signal and the signal from a 45MHz constant-temperature crystal oscillator enter a mixer 1 for mixing, the radio-frequency signal after mixing enters an antenna through a duplexer 2, and is transmitted out through the antenna to be used as a receiving signal of the airborne station; a received signal from an antenna enters a pi-type attenuator 2 through a duplexer 2, the signal enters a low-noise amplifier after proper attenuation and matching, the amplified received signal and a signal from a 45MHz constant-temperature crystal oscillator enter a mixer 2 for mixing, the mixed received signal enters a (347.5 +/-3.5) MHz band-pass filter for filtering, and the filtered received signal enters comprehensive guarantee equipment through a duplexer 1 to serve as a received signal of external field detection equipment; the low-noise amplifier completes the amplification of weak received signals and improves the signal-to-noise ratio of output; the mixer and the 45MHz constant temperature crystal oscillator complete the frequency conversion of the input radio frequency signal 45MHz lower than the output radio frequency signal.

The utility model discloses a technological effect and advantage:

1. the utility model discloses a duplexer and band pass filter's combination scheme for receive the receiver and a pair of antenna of transmitting signal sharing, realize receiving and dispatching mutual noninterference ground simultaneous working.

2. The utility model discloses an adopt duplexer and band pass filter's combination scheme not only to have enough high receiving and dispatching isolation, all have good suppression degree to clutters such as mirror image, local oscillator, intermediate frequency moreover.

3. The utility model discloses do not receive the work place restriction, need not to occupy the satellite resource, it is nimble convenient to work.

Drawings

Fig. 1 is a block diagram of the hardware circuit of the UHF-band satellite communication analog transponder of the present invention;

fig. 2 is a schematic diagram of the UHF-band satellite communication analog transponder for forwarding the received signal;

fig. 3 is a schematic diagram of the signaling forwarding processing of the UHF-band satellite communication analog transponder of the present invention;

FIG. 4 is the utility model discloses a receiving and dispatching signal level allocation schematic diagram of UHF frequency channel satellite communication simulation transponder

Detailed Description

The technical solution of the present invention will be described in further detail with reference to the accompanying drawings and the detailed description.

Referring to the attached drawing 1, the utility model provides a UHF frequency channel satellite communication simulation transponder, through the received signal and the trend of signalling in the simulation transponder, the received signal who comes from the antenna gets into duplexer 2 after, through duplexer 2's receiving and dispatching isolation, export from duplexer 2's high port, get into pi type attenuator and carry out signal level matching, the signal after level matching gets into low noise amplifier and amplifies, the signal after the amplification gets into the mixer, mix with 45MHz signal, accomplish frequency conversion, the signal after frequency conversion gets into duplexer 1's low port after (347.5 + -3.5) MHz band pass filter, export by duplexer 1's antenna port; the transmitting signal from the external field detection equipment enters an antenna port of the duplexer 1, is isolated by receiving and transmitting of the duplexer 1, is output from a high port of the duplexer 1, enters a pi-type attenuator to be subjected to signal level matching, the signal after the level matching enters a (392.5 +/-3.5) MHz band-pass filter, the filtered signal enters a mixer to be mixed with a 45MHz signal to complete frequency conversion, and the signal after the frequency conversion enters a low port of the duplexer 2 and is output by the antenna port of the duplexer 2.

Referring to the schematic diagram of the analog repeater for forwarding the received signal in fig. 2, the received signal with frequency of (389-396) MHz received by the antenna enters the duplexer 2, after being transmitted and isolated by the duplexer 2, enters the pi-type attenuator to complete receiving level matching, the received signal amplified by the low noise amplifier is mixed with the 45MHz signal in the mixer to complete frequency conversion of the received signal, the frequency range of the signal after frequency conversion is (344-351) MHz, the signal enters the duplexer 1 after being filtered by the (347.5 ± 3.5) MHz band-pass filter, and after being transmitted and isolated by the duplexer 1, the signal is output by the antenna port of the duplexer 1 and serves as the received signal of the external field detection device.

Referring to fig. 3, which is a schematic diagram of the analog repeater for forwarding the signaling, the signaling sent by the external field detection device with frequency of (389-396) MHz enters the duplexer 1, after the signaling is transmitted, received and isolated by the duplexer 1, enters the pi-type attenuator to complete the matching of the generation level, then the signaling enters the (392.5 ± 3.5) MHz band-pass filter, the filtered signal is mixed with the 45MHz signal in the mixer to complete the frequency conversion of the signaling, the frequency range of the signal after the frequency conversion is (344-351) MHz, because the signaling amplitude is large, the signaling after the frequency conversion needs the adjustable attenuator to control the amplitude, then the signal enters the duplexer 2, after the transmission, the isolation is transmitted and isolated by the duplexer 2, and the signal is transmitted through the antenna to be used as the receiving signal of the airborne station.

Referring to fig. 4, a schematic diagram of the level assignment of the transmitted and received signals is shown. When satellite communication is carried out in UHF frequency band, the received signal levels of both sides cannot be too large, otherwise, the receiving unit can be saturated, but the signal levels cannot be too small, both conditions can affect the communication effect, even the communication is not carried out at all, the automatic gain control range required by satellite communication equipment in UHF frequency band is 30dB, and when the received signal level is-90 dBm to-120 dBm, the communication effect is best. Therefore, the distribution of the transmitting and receiving levels is very important, and the analog repeater not only performs frequency conversion, but also solves the matching problem of the transmitting and receiving levels.

The calculation formula of the electromagnetic wave space loss is as follows: los =32.44+20lgd +20lgf (1)

In equation (1):

d is the communication distance in kilometers (km);

f is the communication frequency in megahertz (MHz);

los is the electromagnetic wave space loss in dB.

The utility model discloses a theory of operation: when the outfield detecting equipment performs outfield detecting communication on the airborne station, the frequency of a transmitted signal is (389-396) MHz, the frequency f =396MHz is adopted, and assuming that the communication distance d =100m, the theoretical value of the signal space loss calculated according to the formula (1) is about 64.39dB, the airborne station antenna is a directional antenna, and according to the antenna pattern of the airborne station, the signal amplitude between the main lobe and the side lobe of the airborne station antenna is at least 20dB, because the outfield detecting equipment antenna and the airborne station antenna have a height difference, the outfield detecting equipment antenna cannot face the main lobe of the airborne station antenna, so the actual space loss is about 84.39dB, when the transmitting power of the airborne station is set to 10mW (10 dBm), the transmitting power of the integrated guarantee equipment is set to 1W (30 dBm), the antenna gains of both are 0dB, the attenuation from the analog transponder antenna port to the main port is 22dB, and the attenuation from the analog transponder main port to the antenna port is 50dB, the calculation is known: the receiving level of the outfield detection equipment is-96.39 dBm, the receiving level of the airborne station is-104.39 dBm, and both signals are in the receiving range, so that normal communication can be realized, and the circuit design of the UHF frequency band satellite communication analog transponder is feasible, and in practical application, the attenuation from the antenna port to the main machine port is (22 +/-7) dB, and the attenuation from the main machine port to the antenna port is (43 +/-7) dB, so that the UHF frequency band satellite communication analog transponder can be adjusted according to actual conditions.

The points to be finally explained are: first, in the description of the present application, it should be noted that, unless otherwise specified and limited, the terms "mounted," "connected," and "connected" should be understood broadly, and may be a mechanical connection or an electrical connection, or a communication between two elements, and may be a direct connection, and "upper," "lower," "left," and "right" are only used to indicate a relative positional relationship, and when the absolute position of the object to be described is changed, the relative positional relationship may be changed;

secondly, the method comprises the following steps: in the drawings of the disclosed embodiments of the present invention, only the structures related to the disclosed embodiments are referred to, and other structures can refer to common designs, and under the condition of no conflict, the same embodiment and different embodiments of the present invention can be combined with each other;

and finally: the above description is only for the preferred embodiment of the present invention and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An analog repeater for UHF satellite communication, comprising: the duplexer realizes the isolation of receiving and transmitting and enables the receiving and transmitting to work simultaneously without mutual interference; the low noise amplifier amplifies weak received signals, and improves the signal-to-noise ratio of the received signals; the frequency mixer and the 45MHz constant-temperature crystal oscillator complete the frequency conversion of the radio-frequency signals; the band-pass filter filters out the out-band signal and allows the in-band signal to pass through; the pi-type attenuator and the adjustable attenuator are matched to complete the matching of receiving and generating levels.

2. The UHF-band satellite communication analog repeater of claim 1, wherein: the signal from the external field detection equipment enters the pi-type attenuator 1 through the duplexer 1, the signal enters (392.5 +/-3.5) MHz band-pass filter for filtering after being moderately attenuated and matched, the filtered signal and the signal from the 45MHz constant-temperature crystal oscillator enter the mixer 1 for mixing, the radio-frequency signal after mixing enters the antenna through the duplexer 2, and is emitted through the antenna to be used as a receiving signal of the airborne station.

3. The UHF-band satellite communication analog repeater according to claim 1, wherein: a received signal from an antenna enters a pi-type attenuator 2 through a duplexer 2, the signal enters a low-noise amplifier after proper attenuation and matching, the amplified received signal and a signal from a 45MHz constant-temperature crystal oscillator enter a mixer 2 for mixing, the mixed received signal enters a (347.5 +/-3.5) MHz band-pass filter for filtering, and the filtered received signal enters external field detection equipment through a duplexer 1 to serve as a received signal of the external field detection equipment.

4. The UHF-band satellite communication analog repeater according to claim 1, wherein: the combined scheme of the duplexer and the band-pass filter is adopted, so that the receiver and the transmitting signal share one antenna, and the simultaneous operation of receiving and transmitting without mutual interference is realized.

5. The UHF-band satellite communication analog repeater according to claim 1, wherein: the receiving frequency range of UHF frequency band satellite communication is (344-351) MHz, therefore the receiving signal uses (347.5 + -3.5) MHz band-pass filter to filter the out-of-band signal and let the in-band signal pass.

6. The UHF-band satellite communication analog repeater of claim 1, wherein: the UHF frequency range satellite communication transmission frequency range is (389-396) MHz, so that the transmission channel adopts (392.5 +/-3.5) MHz band-pass filter for filtering out the out-band signal and letting the in-band signal pass through.