A large power pulse waveform adjustable ATC transmitter

Abstract

The application discloses a kind of high-power pulse waveform adjustable ATC transmitter, including frequency source circuit, front-stage drive amplification circuit, attenuator, final-stage amplification synthesis circuit, high-power circulator, high-power filter and coupling detection circuit connected in sequence, the coupling detection circuit output pulse waveform, the high-power circulator is also connected with receiver;Frequency source circuit is equipped with temperature sensor, and the output waveform of frequency source circuit is adjusted according to different ambient temperature;According to the output pulse waveform, the output waveform of frequency source circuit is adjusted in real time, so that the output pulse waveform of transmitter meets the index requirement.The application realizes that the amplitude of detection signal is according to different transmission output power, and the output is linear, so that the system can accurately judge the amplitude of transmission output power.

Description

Technical Field

[0001] This invention relates to the field of air traffic control equipment technology, and specifically to a high-power pulse waveform adjustable air traffic control transmitter. Background Technology

[0002] Air traffic control equipment typically requires an as-channel transmitter and a control (or differential) channel transmitter to amplify the radio frequency carrier signal, usually to the kilowatt level, before sending it to the as-channel antenna and the control (or differential) channel antenna. Air traffic control interrogation equipment has strict requirements on the transmitter's pulse power, pulse waveform (including pulse width, pulse rise time, pulse fall time, pulse top unevenness, and pulse sequence unevenness), and pulse power backoff. The pulse rise time is required to be 50ns–100ns, and the pulse fall time is required to be 50ns–200ns. Ensuring that the rise and fall times meet these requirements for a continuous series of pulses is extremely difficult to debug.

[0003] Currently, the main performance indicators of air traffic control interrogation equipment transmitters are achieved through hardware circuits. For some demanding specifications, debugging is difficult, and some specifications cannot be fully achieved through hardware circuits, especially when requirements must be met in different environments. Specifically, it is challenging to simultaneously meet all requirements for transmit waveform pulse width, pulse rise time, pulse fall time, and power control in different environments using only hardware circuits. Summary of the Invention

[0004] To address the aforementioned shortcomings in the existing technology, the present invention provides a high-power pulse waveform adjustable air traffic control transmitter that solves the problem that it is difficult to meet all requirements for the pulse width, pulse rise time, pulse fall time, and pulse top unevenness of the transmitted pulse in different environments.

[0005] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is as follows: a high-power pulse waveform adjustable air traffic control transmitter, comprising a frequency source circuit, a pre-stage drive amplifier circuit, an attenuator, a final stage amplifier and synthesizer circuit, a high-power circulator, a high-power filter, and a coupling detector circuit connected in sequence, wherein the coupling detector circuit outputs a pulse waveform, and the high-power circulator is also connected to a receiver.

[0006] The frequency source circuit is equipped with a temperature sensor, and the output waveform of the frequency source circuit is adjusted according to different ambient temperatures.

[0007] Based on the output pulse waveform, the output waveform of the frequency source circuit is adjusted in real time to ensure that the output pulse waveform of the transmitter meets the specifications.

[0008] Furthermore, the pre-amplifier circuit includes an amplifier, a programmable attenuator, and an isolator.

[0009] Furthermore, the number of stages of the amplifier is determined based on the output power of the frequency source circuit and the driving power required by the final stage amplification and synthesis circuit.

[0010] Furthermore, the final stage amplification and synthesis circuit selects N amplifiers to amplify the output power, and then synthesizes the power output after amplification by the N amplifiers according to the magnitude of the output power.

[0011] Furthermore, the value of N is 1, 2, or 3.

[0012] Furthermore, the high-power circulator matches the final stage amplification and synthesis circuit when the air traffic control is in the transmit state, thereby protecting the final stage amplification and synthesis circuit, and provides a path from the antenna interface to the receiver when the air traffic control is in the receive state.

[0013] Furthermore, the high-power filter suppresses the harmonics emitted when the air traffic control is in the transmission state, so as to meet the transmitter's harmonic performance requirements.

[0014] Furthermore: the coupled detection circuit converts the radio frequency signal into a video signal during transmission. The air traffic control determines whether the transmitter is working properly based on the detection signal and whether the antenna port is reliably connected based on the standing wave signal. The detection signal reports detection signals with different amplitudes to the air traffic control according to the different output power of the transmitter.

[0015] Furthermore, the output waveform of the frequency source circuit is adjusted via a serial port.

[0016] Furthermore, power programming is achieved through the programmable attenuator and the gate voltage of the amplifier.

[0017] The beneficial effects of this invention are as follows: This invention realizes a transmitter for air traffic control interrogation equipment by adjusting the waveform of the transmitted pulse through a serial port. The output power and pulse waveform (including pulse width, pulse rising edge, pulse falling edge, pulse top unevenness, and pulse sequence unevenness) of this transmitter can be easily adjusted according to changes in different operating environments (mainly temperature environments).

[0018] This invention enables the detection signal amplitude to be output linearly according to different transmission output powers, allowing the system to accurately determine the transmission output power amplitude. Attached Figure Description

[0019] Figure 1 This is a block diagram of the overall scheme of the air traffic control transmitter in this invention;

[0020] Figure 2 This is a diagram of the output waveform debugging interface in this invention;

[0021] Figure 3 This is a measured waveform of the transmitted output in this invention. Detailed Implementation

[0022] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0023] like Figure 1 As shown, a high-power pulse waveform adjustable air traffic control transmitter mainly consists of a frequency source circuit, a pre-stage drive amplifier circuit (including amplifiers, programmable attenuators, isolators, etc.), an attenuator, a final-stage amplifier and synthesizer circuit, a high-power circulator, a high-power filter, and a coupler. The number of power amplifier stages in the pre-stage drive amplifier circuit needs to be determined based on the output power of the frequency source and the drive power required by the final-stage amplifier and synthesizer circuit. An isolator is added to the output of the pre-stage drive amplifier circuit to ensure good matching with the final-stage amplifier and synthesizer circuit. The final-stage amplifier circuit can be selected for single-channel amplification, two-channel amplification and synthesis, or three-channel amplification and synthesis, depending on the output power of the final port. Theoretically, it can perform N-channel amplification and power synthesis output based on the output power. The high-power circulator has two main functions: matching and protecting the final-stage amplifier and synthesizer circuit when the air traffic control is in the transmit state, and providing a path from the antenna interface to the receiver when the air traffic control is in the receive state. The high-power filter's main function is to suppress the transmitted harmonics when the air traffic control is in the transmit state to meet the transmitter's harmonic performance requirements. The coupling detection circuit mainly converts radio frequency signals into video signals during transmission. Air traffic control determines whether the transmitter is working properly based on the detection signal and whether the antenna port is reliably connected based on the standing wave signal. The detection signal reports detection signals with different amplitudes to air traffic control depending on the different output power of the transmitter.

[0024] The transmit pulse waveform of the air traffic control transmitter requires a pulse width error of no more than ±100 ns, a pulse rise time (0.1A~0.9A) of 50 ns~100 ns, and a pulse fall time (0.9A~0.1A) of 50 ns~200 ns. This is based on the following two main reasons. Figure 1The transmitter hardware circuit shown presents significant challenges in adjusting the transmitted pulse waveform under varying temperature conditions. In other words, relying solely on hardware circuit adjustments cannot meet the pulse output waveform specifications of the air traffic control transmitter. The main reasons are twofold: firstly, the pulse width, pulse rise time, and pulse fall time are interrelated; secondly, to improve the efficiency of the power amplifier transistors, the power amplifier transistors in the pre-amplifier and final amplifier / combiner circuits are generally operated in a saturated output state, which compresses the output pulse waveform and thus affects its shape.

[0025] This invention adjusts the output waveform of a frequency source in real time using serial port tools (not limited to serial port) based on the pulse waveform output by the transmitter, ensuring that the transmitter's output waveform meets specifications. A temperature sensor is used in the frequency source circuit, allowing the output waveform to be adjusted according to different ambient temperatures to ensure the transmitter's output pulse waveform meets specifications across the entire operating temperature range. The debugging interface is shown below. Figure 2 As shown, by adjusting the "rising edge inflection point," "falling edge inflection point," "rising edge step," and "falling edge step" of the control channel at different temperatures, the corresponding pulse waveform can be achieved. The successfully debugged data can be stored in the FLASH memory. When using the module, the data for the corresponding temperature is directly called to ensure that the output pulse waveform meets the specifications. Figure 3 The output pulse waveform of the air traffic control transmitter designed using this scheme has an output power of 59.3dBm, a pulse width of 880ns, a rise time of 88ns, a fall time of 73ns, and a pulse top unevenness of less than 1dB, which meets the requirements.

[0026] Air traffic control transmitters typically require power back-off and the ability to report detection signals of corresponding amplitudes to air traffic control at different power outputs. This invention achieves power programming through a programmable attenuator in the pre-amplifier circuit and by controlling the gate voltage of the power amplifier tube. Controlling the gate voltage of the power amplifier tube allows for coarse adjustment of the programmable attenuation amplitude, while adjusting the programmable attenuator in the pre-amplifier circuit allows for fine adjustment of the transmitter's output power. The transmitter's output detection uses a detector diode; this invention selects a 1N5711 detector diode, along with capacitors and resistors. The detection voltages corresponding to different power outputs are: 4.0V–5.0V at full power, 3.0V–4.0V with a 3dB back-off, 2.0V–3.0V with a 6dB back-off, and 1.0V–2.0V with a 12dB back-off.

Claims

1. A high-power pulse waveform adjustable air traffic control transmitter, characterized in that, It includes a frequency source circuit, a pre-stage driver amplifier circuit, an attenuator, a final stage amplifier and synthesizer circuit, a high-power circulator, a high-power filter, and a coupling detector circuit connected in sequence. The coupling detector circuit outputs a pulse waveform, and the high-power circulator is also connected to a receiver. The frequency source circuit is equipped with a temperature sensor, and the output waveform of the frequency source circuit is adjusted according to different ambient temperatures. Based on the output pulse waveform, the output waveform of the frequency source circuit is adjusted in real time to ensure that the output pulse waveform of the transmitter meets the specifications. The output waveform of the frequency source circuit is adjusted via a serial port. The pre-amplifier circuit includes an amplifier, a programmable attenuator, and an isolator; power programmability is achieved through the gate voltage of the programmable attenuator and the amplifier.

2. The high-power pulse waveform adjustable air traffic control transmitter according to claim 1, characterized in that, The number of stages of the amplifier is determined based on the output power of the frequency source circuit and the driving power required by the final stage amplification and synthesis circuit.

3. The high-power pulse waveform adjustable air traffic control transmitter according to claim 1, characterized in that, The final stage amplifier and synthesizer circuit selects N amplifiers to amplify the output power, and then synthesizes the power output after amplification by the N amplifiers according to the magnitude of the output power.

4. The high-power pulse waveform adjustable air traffic control transmitter according to claim 3, characterized in that, The value of N is 1, 2 or 3.

5. The high-power pulse waveform adjustable air traffic control transmitter according to claim 1, characterized in that, The high-power circulator matches the final stage amplification and synthesis circuit when the air traffic control is in the transmit state, thus protecting the final stage amplification and synthesis circuit. When the air traffic control is in the receive state, it provides a path from the antenna interface to the receiver.

6. The high-power pulse waveform adjustable air traffic control transmitter according to claim 1, characterized in that, The high-power filter suppresses harmonics during the transmission process to meet the transmitter's harmonic performance requirements.

7. The high-power pulse waveform adjustable air traffic control transmitter according to claim 1, characterized in that, The coupled detection circuit converts the radio frequency signal into a video signal during transmission. Air traffic control determines whether the transmitter is working properly based on the detection signal and whether the antenna port is reliably connected based on the standing wave signal. The detection signal reports different amplitude detection signals to air traffic control according to the different output power of the transmitter.

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