Research On Terahertz Frequency Tripler Technology Based On Planar Schottky Barrier Diodes

Terahertz(THz)waves can be widely applied into the areas of imaging,security inspection,medical diagnosis and high-speed broadband communication due to its superiorities of good directionality,high resolution and strong penetration.However,the development of terahertz technology is greatly limited by the lack of stable,reliable and effective terahertz sources.The frequency multiplier can use mature and developed millimeter-wave amplification module as the driving source to generate terahertz waves,which is the main way to obtain terahertz source.Considering the cost and processing cycle,the frequency multiplier often adopts the hybrid integration technology when the operating frequency is lower than 400 GHz.This master's thesis focuses on the research on terahertz frequency triplers based on the hybrid integration technology,which mainly includes the following contents:(1)The effect of temperature on the performance of frequency multipliers is studied and the thermal simulation is introduced into the design of frequency multipliers.When the multiplier is driven by high power,the anode junction temperature of the diode will increase,which will lead to a decrease in electron mobility and affect the performance of the frequency multiplier.In this thesis,the anode junction temperature under a certain dissipated power is extracted,and then the intrinsic parameters related to the temperature of the diode model are corrected.Finally,the consistency between the measurement and the simulation results of frequency multipliers is improved by the temperature related model which lays the foundation for the following study of accurate diode model.(2)A 220-300 GHz balanced tripler is designed using the Half-Subdivision and Half-Global Design Method.The measured results show that: the tripler has a efficiency of 0.37%-2.3% in the range of 228-280 GHz and the return loss is better than 10 d B with the input driven power of 80 m W.The saturated output power of the tripler is 2.1m W at 252 GHz.Then,a simulation with diode thermal parameters is verified.The thermal simulation results of the frequency multiplier are closer to measurements comparing to the traditional ones,which validates the accuracy of the diode thermal model.(3)An unbalanced 220-270 GHz frequency tripler using domestic planar Schottky diodes is designed and implemented.The unbalanced structure can solve the problem of the bias circuit.The measured results show that: the tripler achieves a maximum efficiency of 5.3% at 220 GHz and a 3 d B bandwidth of 21% with a 80 ? bias resistance.This work has demonstrated the feasibility of domestic circuit chip.The measured results of the frequency multiplier are consistent with the simulated results considering the current saturation effect and temperature characteristics,which verifies the validity of the current saturation effect correction of the intrinsic model and the thermal model.