Study Of The THZ Subharmonic Mixer Based On Schottky Diode

In recent years Terahertz(THz) science and technology is developing a new subject and hot spots,whose frequency rang typically is 0.1THz-10 THz. THz technology is mainly used in the physical imaging, radio astronomy, safety inspection, medical diagnosis and radar detection, etc. In the solid-state terahertz communication systems, as a major part of the THz receiver front-send, the main function of terahertz mixer is to achieve frequency shift work. Compared with the fundamental wave mixing, the LO frequency of subharmonic mixing only needs half of the RF frequency.This thesis describes the devekopments of the solid-state THz mixer who is based on Schottky diodes firstly, and then gives a detailed description of the working mechanism.The main work is to use the 3D simulation software to establish a complete diode model,to extract the effective parasitic parameters,named S parameter. We can establish the 3D model of the reverse diode in parallel through the internal port in HFSS. Then we can use ADS to optimize the whole circuit. Finally the terahertz harmonic mixer is processed and assembled. The test results of the mixer show that in the near range of 20 GHz with center frequency 220 GHz, the mixer achieves an average performance of approximately 9d B conversion loss, with the minimum conversion loss 7.19 dB.Results of this study will provide reference for research of terahertz subharmonic mixer which has more excellent feature and works in higher frequency,and it can be used in the communication and radar system.