The large-caliber light-weight reflector assembly is the core optical component of the large-size space camera. It needs to be highly light-weight to meet the constraint of emission weight. At the same time, the on-orbit reflector assembly needs to have extremely high force and thermal stability, be able to withstand the changes in the in-orbit temperature environment and the resulting stress changes and maintain the profile quality. This paper introduces the development of 1.3m caliber space mirror module. The reflector adopts the uniform thickness back arc design and the positioning support adopts the six-bar Bipod support technology. The simulation analysis verifies that the reflector component has good force and heat stability. The optical axis vertical test is carried out on the surface of the reflector assembly which has been processed and adjusted. The test results are consistent with the mechanical analysis results of the reflector assembly under the condition of gravity field, which meets the technical requirements of the spatial reflector.
An integrated 0.5 THz electromagnetic crystals(EMXT) channel-drop filter based on PBG structure is presented in this paper. A channel-drop filter is a device in which a narrow bandwidth is redirected to another “drop” waveguide while other frequencies are unaffected. It’s capable of extracting a certain frequency from a continuous spectrum in the bus channel and passing it to the test channel. It has potential applications in photonic integrated circuits, radio astronomy, THz spectroscopy, THz communication and remote sensing radar receiver. PBG structures(or photonic crystals) are periodic structures which possess band gaps, where the electromagnetic wave of certain ranges of frequencies cannot pass through and is reflected. The proposed channel-drop filter consists of input waveguide,output waveguide and PBG structure. The proposed filter is simulated using the finite element method and can be fabricated by micro-electromechanical systems (MEMS) technology,due to its low cost, high performance and high processing precision.The filter operation principle and fabrication process are discussed.The simulation results show its ability to filter the frequency of 496GHz with a linewidth of approximately 4GHz and transmission of 27.2 dB above background.The loss at resonant frequency is less than 1dB considering the thickness and roughness of gold layer required by the MEMS process.The channel drop efficiency is 84%.
A novel two-dimensional (2D) square lattice Electromagnetic Bandgap (EBG) structure, including EBG waveguide
transmission line, quarter turn, and power-divider, operated at the center frequency of 0.5THz is proposed. Finite
element method (FEM) was used to analyze and simulate the EBG structure and these components based on EBG. These
components were also compared with traditional ones. Simulation and analysis results show that when the radius of
Si-wire satisfied the condition: R = 0.4a , where a is the lattice constant, the insertion loss and voltage standing wave
ratio (VSWR) of EBG waveguide transmission line and quarter turn are less than -0.05 dB/mm and 1.1, respectively.
Meanwhile, the asymmetric division ratio of power divider is better than 0.1 dB. The square lattice has unique
advantages in the waveguide transmission line design. The 2D EBG structure can be achieved by using poly-silicon
based on MEMS technology with benefits of low loss, planar structures, and high processing accuracy. In addition, it is
also easy to integrate with other devices and circuits, such as antennas, filters, diodes, mixers and so on. Hence, this
novel EBG structure should have many applications for THz passive components, feed system of antenna array, and
integration with other MMIC devices.
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