Ultra wide band swept-frequency microwave radiometer based on frequency doubling technology

Abstract

The invention belongs to an ultra wide band swept-frequency microwave radiometer based on a frequency doubling technology. The ultra wide band swept-frequency microwave radiometer comprises an arbitrary waveform generator and a wide band VCO (voltage controlled oscillator) source, wherein the arbitrary waveform generator is connected with the input ends of the wide band VCO source, an isolator and a power distributor in sequence; the previous three output ends of the power distributor are connected with the LO input ends of a frequency doubler group and a frequency mixer group; the fourth output end of the power distributor is connected with a detector and an oscilloscope; the input end of a receiving antenna receives a signal radiated from a plasma; the output end of the receiving antenna is connected with RF input ends of a band-stop filter, a waveguide power distribution array and the frequency mixer group in sequence; the IF output end of the frequency mixer group is connected with a bandpass filter, a power amplifier and an analog / digital converter in sequence. The ultra wide band swept-frequency microwave radiometer has the advantages that the measurement of the electronic temperature distribution on the whole section of a longitudinal field under the plasma discharge condition of 1.0-2.5T can be realized, and the measurement frequency range can be 40-220GHz.

Description

technical field [0001] The invention belongs to a nuclear fusion plasma microwave diagnosis device, in particular to an ultra-broadband sweep frequency microwave radiometer based on frequency doubling technology. Background technique [0002] In a fusion reactor, the plasma creates a self-sustaining thermonuclear reaction, and the energy released is carried by alpha particles and neutrons. Alpha particles first exchange heat with electrons, transfer heat energy to electrons, and then transfer energy to ions through collisions between electrons and ions. Therefore, heat transport is a key process that determines whether a self-sustaining thermonuclear reaction can proceed. The high-temperature plasma in the tokamak is confined by a magnetic field. Due to the Lorentz force, the electrons perform cyclotron motion, producing electron cyclotron emission (ECE). The ECE intensity carries many important parameters of the plasma, such as: electron temperature, density, electron vel...

AI Technical Summary

Problems solved by technology

The superheterodyne ECE measurement system is relatively complex, requiring multiple secondary local oscillators to down-convert the frequency

In addition, the measured spatial point is discontinuous, and the continuous change of the ECE spectrum cannot be observed

Currently, there are many backwave tube broadband microwave sources on the market, but they are all expensive and have a short lifespan

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