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 coplanar waveguide (CPW)-based composite right/left-handed (CRLH) structure for terahertz (THz) leaky wave
antennas (LWAs) application with high directivity and beam steering capability is introduced. The structure of the
CRLH-TL was composed of a slot and embedded resonators termed metamaterial resonators using planar CPW
technology. There were three steps involved to design the structure of metamaterial resonator and position distribution of
metamaterial resonators in the composite right/left-handed (CRLH) transmission lines. First, equivalent circuit model
method (also called "transmission line model method") was used to create an equivalent circuit model of the element of
metamaterial resonator. Second, from the equivalent circuit model, it was possible to correspond to two basic equivalent
circuit parameters "series impedance and shunt admittance" from artificial transmission line structure "CPW-based
metamaterial resonator". Finally, the dimensions of metamaterial resonator were calculated and optimized according to
the dispersion diagram. Meanwhile, ohmic loss needs to be considered because it is high at THz wave and above
frequency region. The LWAs with CPW-based CRLH could implement high-directivity and backward-to-forward beam
steering which differs from the conventional one. A balanced CPW CRLH LWA is designed at the transition frequency
of 1485 GHz and performances of high-directivity and wide-angle continuous beam-steering are demonstrated.