Research And Design Of Terahertz Source Based On CMOS Technology

The frequency range of terahertz(THz)signal is between 0.1 THz and 10 THz.It has wide academic value and many applications in the fields of terahertz spectrum analysis,terahertz imaging,terahertz communication,terahertz biomedicine,terahertz astronomy and so on.It has become the priority field of international development and the commanding point of science and technology.As the core part of terahertz application,THz source determines the application prospect of terahertz technology.Therefore,the research of THz signal source has theoretical significance and practical value.Due to the shortage of characteristic frequency and low output power of transistor devices in low-power CMOS process,the design of THz source with high output power is a difficult problem in the research of solid-state electronics.In this paper,the terahertz oscillator and its source are discussed based on the Push-Push and Colpitts structure.A 100 GHz oscillator and two 300 GHz signal sources with modulation function are designed in 65 nm CMOS process,and the harmonic oscillation mode is used to generate the terahertz signal.A 2 × 2 array is constructed to improve the output power effectively.The detailed research contents are as follows:1)The realization method of 300 GHz harmonic signal source based on Push-Push oscillator circuit is studied.The technique of extracting second harmonic effectively improves the operating frequency of the signal source.The key part of the SPST switch and the on-chip antenna with cross groove are analyzed in detail.Finally,the simulation and test results of the chip are given.2)According to the characteristics of Colpitts oscillator circuit,the realization methods of 100 GHz fundamental signal source and 300 GHz third harmonic signal source are proposed,and the key circuits and passive components are analyzed in detail.Finally,the simulation results and layout design of the signal source are given.The post-simulation results of the Push-Push oscillator show that: under 1.0 V supply,the oscillator achieved a tunning range from 304.4 GHz to 312.0 GHz,consuming only 20.4 mW,and the output power of second harmonic can reach-16.4 dBm.The on-chip test results show that the operating frequency is 292.42 GHz,package test results show that the DC current is in agreement with the simulation results.The post simulation results of the fundamental oscillator based on Colpitts structure show that the operating frequency is 107.9 GHz,output power is-6.1 dBm,and DC current is 17.2 mA under 1.2V supply voltage.The phase noise can reach-87.2 dBc/Hz at 1 MHz frequency offset.The simulation results of harmonic oscillator show that the maximum output power can reach-3.9 dBm,frequency range is between 316.0 GHz to 326.8 GHz,and the phase noise at 1 MHz frequency offset is about-83.7 dBc/Hz.