Millimeter wave noise source with high-frequency broadband and preparation method thereof

Abstract

The invention discloses a millimeter wave noise source with a high-frequency broadband and a preparation method thereof. According to the millimeter wave noise source, a biasing circuit is connected with an avalanche diode, a suspension band type matching circuit and a microstrip-coaxial converter in sequence; in order to ensure that the working current of the avalanche diode is constant, the overvoltage protection circuit is arranged between the biasing circuit and the avalanche diode in the structure, has the characteristics of high isolation output and low noise output voltage, and is usedfor ensuring that the avalanche diode works in a constant current state. Meanwhile, a hanging belt type matching circuit structure is adopted, the frequency range can be expanded to 110 GHz, and therefore stable output of high-frequency broadband noise signals is achieved; and finally, the final stage is converted through a microstrip-coaxial converter to realize stable signal output. A microstrip-to-coaxial output mode is used for replacing a traditional noise source waveguide-to-coaxial mode, the over-noise ratio is improved, and the standing-wave ratio is optimized.

Description

technical field [0001] The invention relates to the technical field of millimeter-wave broadband noise sources, in particular to a high-frequency broadband millimeter-wave noise source and a preparation method. Background technique [0002] Noise figure measurement plays an important role in the field of microwave and millimeter wave measurement. In the test of noise characteristics, the noise source is an important component, and its accuracy has a great influence on the accuracy of the final noise test. With the continuous development of millimeter wave technology, traditional solid-state noise sources are more difficult to achieve stable output of high-frequency noise signals, especially for high-frequency broadband signals above the Ka band. At present, the traditional millimeter-wave broadband noise sources are generated in the following ways: figure 1 As shown, a constant current source is added to the avalanche diode, white noise is generated through the avalanche d...

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Problems solved by technology

In order to realize the impedance matching of broadband high-frequency noise signals, a new type of suspension matching circuit is designed, which can extend the frequency range to 110GHz; the overall circuit adopts a planar structure, which reduces the difficulty of processing and assembly and reduces the transmission process. loss; the signal output adopts microstrip to coaxial to replace the form of waveguide to coaxial, which ensures the super-noise ratio and standing wave ratio of the output signal, which is more convenient for testing and use, and solves the complex conversion of existing circuit structures and the difficulty of processing and assembly. , the problem of low super-noise ratio

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