Research On Key Technologies Of 1THz Monolithic Integrated Frequency Tripler

The unique physical characteristics of terahertz waves have led to their application in many fields.At present,the development of terahertz technology lacks signal sources,detectors,and measurement systems in the high operating frequency range.Therefore,the research on high-frequency terahertz frequency sources is one of the hot research topics at home and abroad.Based on the application of frequency multiplier in frequency measurement system,this paper studies the key technologies of 1THz triple frequency multiplier,provides local oscillator signal source for measurement system,and constitutes the key components of the system together with terahertz harmonic mixer.This paper first introduces the research background and significance of the subject,investigates the research status of terahertz frequency multiplier and its core component Schottky diode at home and abroad,and analyzes the technical indicators of terahertz frequency multiplier.Secondly,based on the theory of solid-state semiconductor devices,a high cutoff frequency Schottky diode was studied.The frequency doubling principle,physical structure,and high-frequency effects of Schottky diodes in the terahertz frequency band were analyzed.A high cutoff frequency Schottky diode was independently designed.A physical model of a high cutoff frequency Schottky diode was established using HFSS software,and a two-dimensional physical model of the diode core Schottky junction was established using Silvaco TCAD software.The intrinsic SPICE parameters of the diode core were extracted.In order to better characterize the performance of the Schottky diode at high frequencies,the high-frequency parasitic parameters of the diode are extracted by combining the electromagnetic field models of each Substructure of the Schottky diode and the circuit simulation results.Subsequently,a low-pass filter with high stopband suppression was studied,and the design principles and technical specifications of distributed low-pass filters were analyzed.An improved open resonant unit(ISRR)low-pass filter model was established,with symmetrical open branches replaced by asymmetric ones.By introducing larger coupling inductors and capacitors through irregular metal wire branches,better out of band suppression function was achieved.At the same time,traditional high and low impedance low-pass filters and compact microstrip resonant unit(CMRC)low-pass filter models were also designed,and performance comparisons were made.Finally,the method of joint simulation of electromagnetic field and circuit is used to carry out the overall joint simulation and optimization of 1THz monolithic integrated triple frequency multiplier by using HFSS and ADS software,complete the tolerance analysis of the triple frequency multiplier circuit,and propose an experimental test scheme.The simulation results show that when the fundamental signal input power is 100 m W,the output power of the 1THz triple frequency multiplier is more than 4m W in the 0.85～1.1THz output frequency band,and the maximum output power is 5.31 m W at 0.95 THz,corresponding to the maximum frequency multiplication efficiency of 5.31%.