Research For The Mesh Band-pass Filters Of Terahertz

Terahertz Mesh Band-pass filter as an important component of the device and plays a vital role inthe terahertz applications system. In terms of the fabrication technology, because of the operatingwavelength is much smaller , compared with the microwave filters, the volume of the device issmaller, lighter, and easier integrated. When Compared with the light-wave filter, the operatingwavelength is much greater and easier fabricated. Therefore, design terahertz Mesh Band-pass filterhave a wide applicate prospect in the terahertz applications system. Terahertz Mesh filters in additionto have a general frequency-selective filter, noise filtering, gain equalization and other effects, in themillimeter and sub-millimeter wave field, in order to improve the utilization efficiency of reflectorantennas, it is often used as reflector Vice-reflector antenna. In addition, we can also use it to designthe radome, in order to reduce the radar cross section (RCS) of the antenna system; for the far infrared,in order to improve the laser pump power, terahertz filter can be used as a polarizer filter, sub-beaminstrument, and molecular laser’s "cavity mirror" . Terahertz Mesh filter was initially required to rejectthermal radiation that may otherwise saturate sensitive detectors. Along with the in-depth study of thesensitive detectors and terahertz generators, terahertz Mesh filters gradually becoming a researchhot-spot. This paper aims to design a four cascaded terahertz Mesh band-pass filter at the atmosphericabsorption window of 0.25THz. By building the filter’s model, the theoretical analysis of the filterfrom analytical analysis and numerical analysis, and a variety of different factors on the terahertzMesh band-pass filter performance and other aspects are discussed, which provide a reference forfabricating terahertz Mesh band-pass filter.Terahertz mesh band-pass filter has becoming a research focus because of its value ofapplications in the terahertz research. In this paper we first defined the purpose and significance ofresearch at structural arrangement, elaborated the terahertz Mesh filter‘s Research status at home andabroad and it’s tend of development. To determine the parameters of terahertz Mesh band-pass filterBy atmospheric absorption window , briefly introduce the filter simulation software which cansimulate the filter, several method’s advantages and disadvantages which fabricating terahertz filterand it’s steps of fabricating, the property of terahertz beam (Gaussian beam ) and the reason of theterahertz beam (Gaussian beam) transform, the test system which must be used to test the terahertzfilter as well as from the two aspects of analytical analysis and numerical analysis to analyze this filter,analytical analysis is give visual analysis in the form of equivalent circuit. By simulating differentfactors which effect on the performance of the filter, the simulation results show that design this filter has important practical significance.In the light of this cascade filter structure, and applicated the Ansoft’s HFSS electromagneticsimulation software, By analysis and simulate the different arrangement of terahertz Mesh band-passfilter ,the incident beam angle of incidence and polarization of factors on the filter responserespectively, simulation results and theoretical analysis consistent with the results. On this basis, thento optimize the terahertz Mesh band-pass filter’s geometry , the filter’s center frequency is 0.25THz,and the bandwidth at 3dB is 0.1THz, covering the atmospheric absorption window of 0.25THz, out-of-band rejection more than 20dB . That provides a reference value for fabricating terahertz Meshfilter.