Testing system and testing method for front end of heterodyne terahertz quasi-optical receiver

Abstract

The invention relates to the technical field of terahertz detection and testing and relates to a testing system and a testing method for testing a noise temperature of the front end of a heterodyne terahertz quasi-optical receiver. The system comprises a high-temperature blackbody radiation source, a frequency doubling link, a microwave signal source, a beam splitter, a terahertz quasi-optical frequency mixer, a BLAS (Basic Linear Algebra Subprogram) bias, a first-stage low noise amplifier, a second-stage low noise amplifier, a band-pass filter and a power meter. According to the testing system and the testing method, the high-temperature blackbody source is used as a terahertz noise signal source, so that a temperature variation range of the terahertz noise signal source is enlarged and a noise temperature testing range of the testing system is effectively enlarged; a terahertz quasi-optical lens is used as a beam bunching device of the terahertz frequency mixer, so that detection sensitivity of a front end system of the heterodyne terahertz quasi-optical receiver is improved and the problems of weak terahertz noise signal and difficulty in detection on the terahertz noise signal are solved.

Description

technical field [0001] The invention relates to the technical field of terahertz detection and testing, and relates to a testing system and a testing method for the noise temperature at the front end of a heterodyne terahertz quasi-optical receiver. Background technique [0002] Terahertz refers to the frequency of 0.1-10THz (1THz = 10 12 Hz) range of electromagnetic waves, corresponding to a wavelength range of 3mm-30μm, between millimeter waves and infrared waves. Terahertz waves are difficult to generate and detect with traditional electronic and optical methods. Therefore, the terahertz band is considered to be the last gap in the electromagnetic spectrum, called the terahertz gap. With the continuous development of terahertz technology, terahertz technology has been applied in radio astronomy, earth atmosphere observation, terahertz communication, short-range high-sensitivity radar system, medical and biological imaging, earth environment monitoring, and high-speed wir...

AI Technical Summary

Problems solved by technology

Since the direct measurement method and the gain measurement method need to know the gain of the mixer in advance, and the double power method is difficult to accurately measure the power of the output signal when the signal is weak, neither can be effectively applied to the noise temperature test in the terahertz frequency band

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