CN103208406B - A kind of artificial intelligence phase modulation injection locking continuous wave magnetron microwave source - Google Patents

Abstract

The invention relates to a microwave radiation source, and the invention discloses an artificial intelligence phase modulation injection locking continuous wave magnetron microwave source. The technical solution of the present invention is an artificial intelligence phase modulation injection-locked continuous wave magnetron microwave source, including a signal source, a magnetron, a circulator, a coupler, a mixer, a filter and a phase detector; The injection signal output by the signal source is injected into the magnetron through the circulator, and the frequency of the power signal output by the magnetron is adjusted. The power signal enters the coupler through the circulator, and a part of the signal output by the coupler is mixed by a mixer. signal, the mixed frequency signal is input to the phase detector through the filter, the output terminal of the phase detector is connected to the signal source, and the learning algorithm based on artificial intelligence controls the frequency and phase of the injected signal output by the signal source. The invention improves the frequency and phase stability of the output microwave of the magnetron, can meet the requirement of coherent combination, and is especially suitable for the application field of microwave energy transmission.

Description

An Artificial Intelligence Phase Modulation Injection Locked CW Magnetron Microwave Source

technical field

The present invention relates to a microwave radiation source, in particular to a microwave source for frequency locking and phase modulation (frequency locking and phase adjustment) by injecting microwaves from an independent signal source into a magnetron. It is mainly used in microwave coherent power combining technology in the field of microwave energy transmission.

Background technique

In the technical field of high-power microwave applications such as microwave energy transmission, it is often necessary to obtain as high a microwave power as possible. Since the output power of a single microwave source is limited by the power capacity of the device itself, using microwave power combining technology is an effective way to solve this problem. In the existing microwave power combining technology, there are two categories of coherent power combining and non-coherent power combining technologies. Microwave coherent power synthesis technology requires certain conditions for the transmission frequency and phase of each microwave power source in the system. Usually, the microwave transmission frequency and phase of each microwave power source are required to be the same, which requires the use of high-power microwave phase-locking and phase-shifting. technology. Commonly used microwave generators mainly include solid-state devices and electric vacuum tubes. At present, the method of obtaining high-power microwave mainly adopts the step-by-step synthesis method of solid-state devices. Due to the limitation of the low power of a single solid-state device, the microwave output power of multi-stage synthesis of solid-state devices only reaches the kilowatt level. At present, special fields such as microwave energy transmission often require microwave sources on the order of megawatts. Considering many factors such as lifespan and cost, American scientists first proposed the use of inexpensive commercial continuous wave magnetrons (magnetrons for short) in microwave energy transmission to achieve synthesis. In order to improve the combining efficiency, it is often hoped to meet the requirements of microwave coherent combining.

Magnetron is a microwave device with complex amplitude and phase characteristics. Although the commercial magnetron has the advantages of low price, high single-tube output power, long life, and high power-to-mass ratio, it has the disadvantages of wide spectrum range and phase instability. Its working frequency changes randomly in a large range (such as magnetrons with center frequencies of 2450MHz and 5800MHz, the frequency ranges are usually 2450±25MHz and 5800±30MHz respectively), and the phase also changes randomly within the range of 0-2π. Therefore, it is necessary to modify and control the external auxiliary system of the commercial magnetron to achieve frequency-locked phase modulation in order to meet the requirements of coherent power combining of multiple magnetron microwave sources, and then the phase-controlled magnetron (PCM) appeared. At present, there are two main methods to realize the phase control magnetron. One is proposed by the American scientist Brown, which adopts two feedback loops of frequency and phase respectively, and controls the external magnetic field of the magnetron through the added "buckboost" coil to perform frequency locking and phase modulation. The other method is proposed by Kyoto University in Japan, by controlling the high-voltage power supply to change the anode current of the magnetron to achieve frequency-locked and phase-modulated methods. These two methods realize frequency-locked phase modulation by changing the working parameters of the magnetron, and both involve the modification of the structure of the magnetron itself, which is complex and difficult to implement.

Contents of the invention

The technical problem to be solved by the present invention is to provide an artificial intelligence phase modulation injection locking continuous wave magnetron microwave source, which uses power injection method to perform microwave injection frequency locking and phase modulation on commercial magnetrons.

The present invention solves the technical problem, and adopts the technical scheme that an artificial intelligence phase-modulation injection-locked continuous wave magnetron microwave source includes a signal source, a magnetron, a circulator, a coupler, a mixer, and a filter. and a phase detector; the injection signal output by the signal source is injected into the magnetron through the circulator, and the frequency of the power signal output by the magnetron is adjusted, and the power signal enters the coupler through the circulator, and a part of the signal output by the coupler The mixed frequency signal is generated by the mixer, and the mixed frequency signal is input to the phase detector through the filter, and the output terminal of the phase detector is connected to the signal source, and the learning algorithm based on artificial intelligence controls the frequency and frequency of the injected signal output by the signal source phase.

In the technical solution of the present invention, a high-stability signal source is used to generate an injection signal with a frequency close to the natural resonance frequency of the magnetron, and the signal is directly injected into the magnetron through a circulator. When the amplitude of the injection signal reaches a considerable order of magnitude, the magnetron The oscillation frequency is phase-synchronized with the injected signal. Within the frequency-locking range, the output frequency of the magnetron is the same value as the injection signal, and the output frequency of the magnetron is directly controlled by the frequency of the injection signal, which realizes frequency-locking and phase modulation of ordinary commercial magnetrons by injecting signals. control.

Due to the delay of the injection signal through the circulator, magnetron and directional coupler, and the influence of many factors such as DC high voltage source, anode current, filament voltage and magnetron temperature during the operation of the magnetron, its output power Signal characteristic parameters (frequency, phase) still have dynamic changes during locking, and a feedback loop must be established to dynamically adjust its deviation at all times, and there is a nonlinear change process of phase due to the above reasons. For this reason, the phase detector of the present invention adopts a learning algorithm based on artificial intelligence commonly used in the field of control technology, which further improves the accuracy of frequency-locked and phase-modulated.

The feedback control loop of the present invention takes a part of the signal from the output of the coupler, processes it through a mixer, a filter and a phase detector, and controls the frequency and phase of the injected signal output by the signal source. The invention introduces the concept of frequency mixing in communication signal processing to the processing of high-power microwave sources, takes out a part of the power signal output by the coupler, and inputs it into the mixer together with a standard signal, and takes the difference frequency output after mixing signal, and then digitally sample the phase of the signal through the phase detector, and then realize the control of the power signal. The above-mentioned standard signal can be generated by a standard frequency source, or provided by a signal source.

Further, a power amplifier is connected between the signal source and the circulator for amplifying the injected signal to a set power.

Adding a power amplifier between the signal source and the circulator can amplify the power of the injected signal output by it, and make up for the defect that the output signal power of the signal source is insufficient, so as to meet the requirements of the frequency locking of the magnetron.

Specifically, the DC high voltage ripple of the magnetron is <1%.

The DC high-voltage power supply with low ripple is adopted, and its ripple is less than 1%, which can reduce the adverse influence of the noise of the power supply itself on the working characteristics of the magnetron, and improve the accuracy of frequency-locked phase modulation.

It is recommended that the artificial intelligence phase modulation injection-locked continuous wave magnetron microwave source be used for space microwave energy transmission.

Space microwave energy transmission often requires a high-power microwave transmission system. The microwave source of the present invention can be used to form a coherent microwave power synthesis system, thereby obtaining a high-power microwave transmission device to meet the high-power requirements of space microwave energy transmission.

The beneficial effect of the present invention is that the common commercial magnetron is injection-locked and phase-modulated by using a high-stability signal source through the method of injecting signals; the phase control of the injection signal output by the high-stability signal source is realized by adopting a feedback loop Magnetron phase stabilization and phase shifting functions. The invention improves the frequency and phase stability of the output microwave of the magnetron, can meet the requirement of coherent combination, and is especially suitable for the application field of microwave energy transmission.

Description of drawings

Fig. 1 is a schematic diagram of the structure of the embodiment.

Detailed ways

The technical solution of the present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

The invention adopts the microwave injection frequency locking technology, before the magnetron starts to vibrate, a low-level and high-stability external reference frequency microwave signal (called the injection signal in the invention), whose frequency is close to the inherent frequency of the magnetron Resonant frequency (or called center frequency). The signal is directly injected into the magnetron through the circulator, and when the amplitude of the injected signal reaches a certain order of magnitude, the oscillation frequency of the magnetron is synchronized with the phase of the injected signal. Within the frequency-locking range, the output frequency of the magnetron is the same as the frequency of the injected signal, and the output frequency of the magnetron is directly controlled by the frequency of the injected signal.

Example

In this example, a magnetron microwave source operating at a C-band frequency of 5.799 GHz is taken as an example to illustrate the structure and implementation method of the present invention. Correspondingly, the injected signal frequency=5.799GHz, the center frequency of the magnetron=5.8GHz, and the standard signal frequency=5.799GHz+100kHz.

An artificial intelligence phase modulation injection-locked continuous wave magnetron microwave source of the present invention comprises a signal source 1, a power amplifier 12, a circulator 2, a coupler 3, a magnetron 4, a mixer 5, a filter 6 and Phase detector 7, as shown in FIG. 1 . The power of the signal source 1 is about 0dBm, and the output frequency of the injected signal is set to 5.799GHz. The gain of the power amplifier 12 is 40dB, and the output power is about 10W. The injection signal output by the signal source 1 is injected into the magnetron 3 through the circulator 2, and the frequency of the power signal output by the magnetron is adjusted so that it is set to 5.799 GHz. The power signal output by the magnetron 3 enters the coupler 3 through the circulator 2, and most of it is output as microwave power, and a part of the signal output by the coupler 3 enters the feedback loop. The feedback loop in this example includes a mixer 5 , a filter 6 and a phase detector 7 , which is a common phase-locked loop (PLL) in communication technology. The mixer 5 mixes the power signal and the standard signal to generate a mixed frequency signal with a frequency of 100kHz, and the mixed frequency signal is input to the phase detector 7 after being filtered out by the filter 6 . In this example, the phase detector 7 is based on the artificial intelligence learning algorithm, compares the 100kHz mixed frequency signal with the standard 100kHz signal, generates a control signal and outputs it to the signal source 1, and controls the frequency and phase of the injected signal output by the signal source 1. Through repeated adjustments, the output frequency of the magnetron 4 is finally locked to 5.799 GHz, and the phase is synchronized with the injection signal output by the signal source 1 .

In this example, the high-voltage DC power supply of the magnetron 4 is a 4200V DC high-voltage power supply with a ripple less than 1%. The magnetron 4 acts as an amplifier under the action of the injected signal, and outputs about 650W of microwave power to the coupler 3 through the circulator 2, and finally the microwave power is radiated out through the load antenna system.

In this example, the frequency stability of the microwave source reaches 10 ^-8 , the phase stability is better than ±2°, the output power is about 655W, the phase can be adjusted within ±180°, and the phase shift step is 1°. The microwave source meets the requirements of microwave coherent power combining.

Claims (4)

1. A kind of artificial intelligence phase modulation injects and locks continuous wave magnetron microwave source, comprises signal source, magnetron, circulator, coupler, mixer, filter and phase detector; The injection of described signal source output The signal is injected into the magnetron through the circulator, and the frequency of the power signal output by the magnetron is adjusted. The power signal enters the coupler through the circulator, and a part of the signal output by the coupler generates a mixed signal through a mixer. The frequency signal is input to the phase detector through the filter, and the output terminal of the phase detector is connected to the signal source. Based on the learning algorithm of artificial intelligence, the frequency and phase of the injected signal output by the signal source are controlled. 2. A kind of artificial intelligence phase modulation injection locking continuous wave magnetron microwave source according to claim 1, is characterized in that, is connected with power amplifier between described signal source and circulator, is used for amplifying injection signal to set fixed power. 3. An artificial intelligence phase modulation injection-locked continuous wave magnetron microwave source according to claim 1, characterized in that the DC high voltage ripple of the magnetron is <1%. 4. A kind of artificial intelligence phase modulation injection locking continuous wave magnetron microwave source according to claim 1, it is characterized in that, described a kind of artificial intelligence phase modulation injection locking continuous wave magnetron microwave source is used for space microwave energy transfer.