Terahertz quasi-elliptical waveguide filter that is easy to implement by CNC

Abstract

The invention provides a terahertz quasi-elliptic waveguide filter that is easy to implement by CNC. The filter comprises an upper structural block and a lower structural block. The upper structural block and the lower structural block are detachably connected, and an H-face single-sided crack waveguide structure is arranged between the upper structural block and the lower structural block. The H-side single-sided crack waveguide structure comprises a source input waveguide, a load output waveguide and four resonant cavities in the same size. The four resonant cavities are arranged in a foldedmanner along an H-face, and adjacent resonant cavities are magnetically coupled, and cross electric coupling is used between non-adjacent resonant cavities. The high-frequency filter can be processedby a CNC process and gold is plated on an outer layer. The filter operates in a 220 GHz band and has a low insertion loss characteristic of -0.6 dB, and two distinct zero points near a passband existout of a band, so that the edge selection characteristic of the filter is very good, that is, the filter has a quasi-elliptical response. The filter is applied to a terahertz detection system to achieve continuous spectrum astronomical observation with 10% bandwidth in the 220 GHz band.

Description

technical field [0001] The invention relates to the technical field of terahertz frequency band waveguide filters, in particular to a terahertz quasi-elliptical waveguide filter which is easy to realize by CNC. Background technique [0002] The terahertz frequency band refers to electromagnetic waves with a frequency range of 0.1 to 10 THz, which contains a large number of characteristic spectral lines of interstellar molecules. It is a unique frequency band for radio astronomy observation and research, and is of great significance for understanding the state and evolution of the universe. [0003] The filter has frequency selective characteristics and is one of the important passive components in the detection system. It can filter out interference frequencies and environmental noise outside the working bandwidth, give priority to extracting feature information and improve system performance. In the terahertz coherent detector, the filter can suppress the interference of th...

AI Technical Summary

Problems solved by technology

However, the frequency response transition of this type of filter is slow, and the out-of-band rejection is poor. In order to obtain better frequency selection characteristics, it can only be achieved by increasing the order of the filter, which will lead to an increase in the size of the filter and an increase in loss. Large and other shortcomings

Moreover, in order to measure the actual micro-process waveguide structure and connect it with other waveguide ports in the system, precise fixtures, H-face elbows and other structures need to be designed and processed. These additional structures will lead to increased losses. The loss characteristics of terahertz waveguide filters fabricated by micro-process are generally not excellent

The waveguide filter processed by traditional milling machine (CNC) can obtain superior insertion loss characteristics because it does not need any other conversion structure, and it is easy to use in the waveguide structure system, but due to its limited precision, it can be used in the terahertz frequency band applications are limited

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