Adjustable gain amplification system for radio astronomical terminal

Abstract

The utility model discloses an adjustable gain amplification system for a radio astronomical terminal, which relates to the technical field of integrated circuit design and comprises a Raspberry Pi controller, an AD conversion module, a first power detector, a second power detector, a PC and the radio astronomical terminal. And at least two paths of radio frequency signal processing modules, namely a first radio frequency signal processing module and a second radio frequency signal processing module, reasonable gain is applied before the ADC collects signals, the signals are controlled within a certain range by adjusting the amplitude of the signals at the input end of the radio astronomical terminal in real time, it is ensured that the collected signal clock is kept within the optimal sampling range of the analog-to-digital converter, the higher signal-to-noise ratio of the terminal is met, and the signal-to-noise ratio of the terminal is improved. It is ensured that the input signal does not cause a signal saturation phenomenon when the radio astronomical terminal carries out analog-to-digital conversion, and the problem that observation data is unavailable due to signal saturation is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of integrated circuit design, and more specifically to an adjustable gain amplification system for a radio astronomy terminal. Background Technique

[0002] At present, radio telescopes are important observation tools in radio astronomy. Weak electromagnetic wave signals radiated from cosmic celestial bodies are reflected to the feed of the focal receiver, and then are amplified and filtered and then transmitted to the terminal system after that. The ADC (analog-to-digital converter) is an important device for digital reception of astronomical terminals. In order to ensure that the output signal of the receiver can meet the dynamic range of the ADC and ensure that the ADC is not saturated, usually a stage of adjustable gain attenuation module needs to be added between the output end of the receiver and the input end of the ADC to adjust the gain to ensure that the input signal of the ADC is within a suitable range.

[0003] Generally, at the beginning of radio telescope observation, in a local or remote manner, the terminal detects whether the intensity of the input signal is appropriate. For signals with a larger amplitude, appropriate attenuation is increased, and then observation can start. During the observation process, no signal amplitude detection and adjustment are performed. At this time, if the radio telescope receives a very strong satellite signal, the analog-to-digital converter of the terminal will immediately saturate, resulting in unavailable observation data.

[0004] Therefore, how to adjust the amplitude of the input signal of the radio astronomy terminal is an urgent problem to be solved by those skilled in the art. Content of the Utility Model

[0005] In view of this, the utility model provides an adjustable gain amplification system for a radio astronomy terminal to solve the problems existing in the background technique.

[0006] In order to achieve the above purpose, the utility model adopts the following technical scheme:

[0007] An adjustable gain amplification system for a radio astronomy terminal, characterized by comprising: a Raspberry Pi controller, an AD conversion module, a first power detector, a second power detector, a PC, a radio astronomy terminal, and at least two radio frequency signal processing modules: a first radio frequency signal processing module and a second radio frequency signal processing module;

[0008] The first interface of the first radio frequency signal processing module is connected to the first power detector; the first interface of the second radio frequency signal processing module is connected to the second power detector; the first power detector and the second power detector are respectively connected to the AD conversion module; the AD conversion module is connected to the Raspberry Pi controller; the Raspberry Pi controller is connected to the PC through Ethernet; the second interface of the first radio frequency signal processing module is connected to the ADC0 port of the radio astronomy terminal; the second interface of the second radio frequency signal processing module is connected to the ADC1 port of the radio astronomy terminal.

[0009] Optionally, the internal structures of the first radio frequency signal processing module and the second radio frequency signal processing module are the same; including an adjustable programmable attenuator, an amplifier, a power splitter, a filter, and a DC Block; the adjustable programmable attenuator, the amplifier, the power splitter, the filter, and the DC Block are connected in sequence.

[0010] Optionally, the power splitter in the first radio frequency processing module is connected to the first power detector; the power splitter in the second radio frequency processing module is connected to the second power detector.

[0011] Optionally, the DC Block in the first radio frequency processing module is connected to the ADC0 port of the radio astronomy terminal; the power splitter in the second radio frequency processing module is connected to the ADC1 port of the radio astronomy terminal.

[0012] Optionally, the Raspberry Pi controller is further connected to an OLED screen for displaying the power value detected by the power detector, as well as the comparison results of the attenuation value and the rotary potentiometer.

[0013] Optionally, the Raspberry Pi controller uses a Raspberry Pi development board as the main control, including an Ethernet interface, four USB interfaces, and 40 GPIO interfaces, where the GPIO interfaces have the functions of being multiplexed as serial ports, I2C, and SPI interfaces.

[0014] Optionally, the AD conversion module is further connected to a first rotary potentiometer and a second rotary potentiometer; among them, the AD conversion module selects a PCF8591 chip, which is an 8-bit A / D and D / A converter with an I2C bus interface, including 4 channels of analog-to-digital conversion input interfaces and one channel of digital-to-analog conversion output interface. The Raspberry Pi controller communicates with the AD conversion module through the I2C bus for reading multi-channel analog-to-digital conversion data.

[0015] Optionally, the adjustable programmable attenuator selects an RCDAT-30G-30 programmable attenuator, with a frequency range of 0.1 - 39 GHz, a power range of 0 - 30 dB, a step of 0.5 dB, and with Ethernet and USB interfaces.

[0016] Optionally, the amplifier is a ZVA-183WX-S+ RF power amplifier with an operating frequency of 0.1 to 18 GHz, a gain of 24 to 34 dB, a gain flatness of ±1 to ±2.5 dB, a noise figure of 3 to 6 dB, and an output power of 34 to 27 dBm.

[0017] As can be seen from the above technical solutions, compared with the prior art, the present utility model discloses an adjustable gain amplification system for a radio astronomy terminal, which applies a reasonable gain before the ADC collects the signal. By adjusting the amplitude of the input signal of the radio astronomy terminal in real time, the signal is controlled within a certain range, ensuring that the signal clock during signal collection remains within the optimal sampling range of the analog-to-digital converter, meeting the relatively high signal-to-noise ratio of the terminal, and ensuring that the input signal will not cause signal saturation during the analog-to-digital conversion of the radio astronomy terminal, thereby solving the problem that the observation data is unavailable due to signal saturation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0019] Figure 1 It is a schematic diagram of the system structure provided by the present utility model;

[0020] Figure 2 It is a flowchart of the local mode provided by the present utility model;

[0021] Figure 3 It is a flowchart of the remote mode provided by the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0023] An embodiment of the present utility model discloses an adjustable gain amplification system for a radio astronomy terminal, as Figure 1 shown, including: a Raspberry Pi controller, an AD conversion module, a first power detector, a second power detector, a PC, a radio astronomy terminal, and at least two RF signal processing modules: a first RF signal processing module and a second RF signal processing module;

[0024] The first interface of the first radio frequency signal processing module is connected to the first power detector; the first interface of the second radio frequency signal processing module is connected to the second power detector; the first power detector and the second power detector are respectively connected to the AD conversion module; the AD conversion module is connected to the Raspberry Pi controller; the Raspberry Pi controller is connected to the PC via Ethernet; the second interface of the first radio frequency signal processing module is connected to the ADC0 port of the radio astronomy terminal; the second interface of the second radio frequency signal processing module is connected to the ADC1 port of the radio astronomy terminal.

[0025] In a specific embodiment, the internal structures of the first radio frequency signal processing module and the second radio frequency signal processing module are the same; they include an adjustable programmable attenuator, an amplifier, a power splitter, a filter, and a DC Block; the adjustable programmable attenuator, the amplifier, the power splitter, the filter, and the DC Block are connected in sequence.

[0026] In a specific embodiment, the power splitter in the first radio frequency processing module is connected to the first power detector; the power splitter in the second radio frequency processing module is connected to the second power detector.

[0027] In a specific embodiment, the DC Block in the first radio frequency processing module is connected to the ADC0 port of the radio astronomy terminal; the power splitter in the second radio frequency processing module is connected to the ADC1 port of the radio astronomy terminal.

[0028] In a specific embodiment, the Raspberry Pi controller is also connected to an OLED screen, which is used to display the power value detected by the power detector, as well as the comparison result between the attenuation value and the knob potentiometer.

[0029] In a specific embodiment, the Raspberry Pi controller selects the Raspberry Pi development board as the main control, including an Ethernet interface, four USB interfaces, and 40 GPIO interfaces, where the GPIO interfaces have the functions of being multiplexed as serial ports, I2C, and SPI interfaces.

[0030] In a specific embodiment, the AD conversion module is also connected to a first knob potentiometer and a second knob potentiometer; among them, the AD conversion module selects the PCF8591 chip, which is an 8-bit A / D and D / A converter with an I2C bus interface, including 4 channels of analog-to-digital conversion input interfaces and one channel of digital-to-analog conversion output interface. The Raspberry Pi controller communicates with the AD conversion module via the I2C bus for reading multi-channel analog-to-digital conversion data.

[0031] In a specific embodiment, the adjustable programmable attenuator is the RCDAT-30G-30 programmable attenuator from Mini Circiuts. The frequency range is 0.1 - 39 GHz, the power range is 0 - 30 dB, the step is 0.5 dB, and it has Ethernet and USB interfaces.

[0032] In a specific embodiment, the amplifier is the ZVA-183WX-S+ RF power amplifier from Mini Circiut. The operating frequency is 0.1 to 18 GHz, the gain is 24 to 34 dB, the gain flatness is ±1 to ±2.5 dB, the noise figure is 3 to 6 dB, and the output power is 34 to 27 dBm.

[0033] Specifically, the entire system consists of a Raspberry Pi controller, an adjustable attenuator, an amplifier, a power splitter, a power detector, a filter, an AD conversion module, a potentiometer, an OLED screen, and a DC Block, etc.

[0034] The adjustable gain amplifier system has two operating modes, the local mode and the remote mode. When in the remote mode, the PC interacts with the Raspberry Pi controller via Ethernet for remotely setting the signal attenuation threshold range. When in the local mode, the attenuation of the adjustable attenuator is locally set by measuring the different voltage values input by the potentiometer through the AD conversion module, and the results and the power values detected by the power detector are displayed on the OLED screen. The Raspberry Pi controller compares the set threshold range with the power values detected by the power detector, so as to achieve the purpose of controlling the amplitude of the input signal within a reasonable range.

[0035] The flowchart of the local mode is as Figure 2 shown. When entering the local mode, the system reads the values of two rotary potentiometers and the attenuation values of two programmable attenuators at the same time, and judges whether the attenuation values are within the value range of the potentiometers. If so, the OLED will display the "Locked" state; if not, the OLED will display the "unlocked" state, and the value of the attenuator is set to the limit value of the rotary potentiometer.

[0036] The flowchart of the remote mode is as Figure 3 shown. In the remote mode, one can log in to the Raspberry Pi via SSH or vnc, enter commands in the terminal window of linux, query the usage of relevant commands and the values of the programmable attenuator and the power detector, and set the threshold range of the input signal amplitude.

[0037] Among them, the power splitter divides the signal of the amplifier into two parts, which are given to the power detector and the filter respectively.

[0038] The filter filters out the signals within the required bandwidth according to the design requirements, and does not want the signals outside the bandwidth to reduce the influence.

[0039] DC Block, a DC blocker, blocks DC signals from passing through and allows RF signals to pass through.

[0040] The RF signal passes through an adjustable programmable attenuator, and the signal amplitude is attenuated. The attenuation value here can be controlled by a Raspberry Pi. The amplifier can amplify the signal to ensure that the signal is not too weak. The power splitter divides the signal into two paths. One path passes through a power detector and an AD module for the Raspberry Pi to detect the power amplitude of the signal at this time. The other path passes through a filter to filter out the signals within the selected frequency bandwidth and filter out out-of-band interference. Then it passes through a DC Block to completely block DC signals from passing through. Finally, the signal enters the terminal through the ADC signal input port of the radio astronomy terminal.

[0041] Generally, for the radio astronomy observations we commonly use, after the radio signal enters the receiver of the radio telescope, two signals will be output. To meet the requirements of future ultra-wideband and multi-beam receivers, the number of signal paths can be appropriately increased.

[0042] The utility model can not only ensure that the output signal of the receiver can meet the dynamic range of the ADC and ensure that the ADC is not saturated; but also ensure that the collected signal always remains within the optimal sampling range of the analog-to-digital converter, meeting the higher signal-to-noise ratio of the terminal; and by setting the threshold in remote and local modes, the dynamic adjustment of the signal amplitude is realized.

[0043] In this specification, the various embodiments are described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. The same or similar parts among the various embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the method part.

[0044] The above description of the disclosed embodiments enables those skilled in the art to implement or use the utility model. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the utility model. Therefore, the utility model will not be limited to these embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An adjustable gain amplification system for a radio astronomy terminal, characterized in that, Including: A Raspberry Pi controller, an AD conversion module, a first power detector, a second power detector, a PC, a radio astronomy terminal, and at least two radio frequency signal processing modules: a first radio frequency signal processing module and a second radio frequency signal processing module; The first interface of the first radio frequency signal processing module is connected to the first power detector; the first interface of the second radio frequency signal processing module is connected to the second power detector; the first power detector and the second power detector are respectively connected to the AD conversion module; the AD conversion module is connected to the Raspberry Pi controller; the Raspberry Pi controller is connected to the PC through Ethernet; the second interface of the first radio frequency signal processing module is connected to the ADC0 port of the radio astronomy terminal; the second interface of the second radio frequency signal processing module is connected to the ADC1 port of the radio astronomy terminal.

2. The adjustable gain amplification system for a radio astronomy terminal according to claim 1, characterized in that, The internal structures of the first radio frequency signal processing module and the second radio frequency signal processing module are the same; including an adjustable programmable attenuator, an amplifier, a power divider, a filter, and a DC Block; the adjustable programmable attenuator, the amplifier, the power divider, the filter, and the DC Block are connected in sequence.

3. The adjustable gain amplification system for a radio astronomy terminal according to claim 2, characterized in that, The power divider in the first radio frequency processing module is connected to the first power detector; the power divider in the second radio frequency processing module is connected to the second power detector.

4. The adjustable gain amplification system for a radio astronomy terminal according to claim 2, wherein The DC Block in the first radio frequency processing module is connected to the ADC0 port of the radio astronomy terminal; the power divider in the second radio frequency processing module is connected to the ADC1 port of the radio astronomy terminal.

5. An adjustable gain amplification system for a radio astronomy terminal according to claim 1, characterized in that The Raspberry Pi controller is also connected to an OLED screen, which is used to display the power value detected by the power detector, as well as the comparison result between the attenuation value and the knob potentiometer.

6. The adjustable gain amplification system for a radio astronomy terminal according to claim 1, wherein, The Raspberry Pi controller selects a Raspberry Pi development board as the main control, including 1 Ethernet interface, four USB interfaces, and 40 GPIO interfaces, where the GPIO interfaces have the functions of being multiplexed as serial ports, I2C, and SPI interfaces.

7. An adjustable gain amplification system for a radio astronomy terminal according to claim 1, characterized in that, The AD conversion module is also connected to a first knob potentiometer and a second knob potentiometer; among them, the AD conversion module selects a PCF8591 chip, an 8-bit A / D and D / A converter with an I2C bus interface, including 4 analog-to-digital conversion input interfaces and one digital-to-analog conversion output interface. The Raspberry Pi controller communicates with the AD conversion module through the I2C bus for reading multi-channel analog-to-digital conversion data.

8. The adjustable gain amplification system for a radio astronomy terminal according to claim 2, wherein The adjustable programmable attenuator selects an RCDAT-30G-30 programmable attenuator, with a frequency range of 0.1 - 39 GHz, a power range of 0 - 30 dB, a step of 0.5 dB, and with Ethernet and USB interfaces.

9. The adjustable gain amplification system for a radio astronomy terminal according to claim 2, wherein The amplifier selects a ZVA-183WX-S+ radio frequency power amplifier, with an operating frequency of 0.1 to 18 GHz, a gain of 24 to 34 dB, a gain flatness of ±1 to ±2.5 dB, a noise figure of 3 to 6 dB, and an output power of 34 to 27 dBm.

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