Research And Design Of Single-band And Multi-band Terahertz Detectors

Terahertz detector is an important part of the terahertz receiving system,which can receive terahertz radiation to achieve non-destructive testing of the internal properties of matter,and has become a research hotspot of cutting-edge technology.Traditional terahertz detectors have narrow frequency band and limited detection information,but it is difficult to realize the detection of terahertz ultra-wide band under the requirements of high responsiveness.This paper increases the number of detection frequency bands to improve the bandwidth and expand the detection frequency range.Based on CMOS technology,single-band and multi-band terahertz detectors are deeply studied,and single,dual and three-band terahertz detectors with high responsiveness are designed respectively.The main research contents are as follows:(1)The working principle and detection mode of terahertz detector are studied.A Terahertz detector working at 300GHz is designed based on 180nm CMOS technology.The detector adopts the structure of double-fed differential antenna,differential self-mixing and monopolar amplifier circuit,which has high responsiveness and can detect relatively weak terahertz signals.When the input power is-40dBm,the maximum responsivity is 11.25kV/W and the noise equivalent power is 115 pW/(?).(2)On the basis of the research of single band detector,a detection band is added to improve the detection range,and a dual-frequency detector working at 300GHz and 500GHz is designed.The detector integrates a dual-frequency single-feed on-chip antenna,a common-source mixing and a common-source and common-gate amplifying circuit.The matching network between the antenna and the circuit ensures the maximum power transmission of the signal.When the input power is-40dBm and the frequency is 300GHz and 500GHz,the responsivity of the detector is 21.8kV/W and 30.4kV/W,and the noise equivalent power is 120 pW/(?)and 93 pW/(?),respectively.(3)Research on the three-band detector and design a multi-band detector working at 300,500 and 700GHz.The detector integrates three-band on-chip antenna,differential mixing circuit and operational amplifier.By adjusting the antenna structure and size,the resonant impedance of each frequency band of the antenna is equal to the conjugate input impedance of the circuit,which not only saves the area but also realizes the maximum power transmission.At the same time,the addition of operational amplifiers further improves the detector responsiveness.When the input power is-40dBm and the frequency is 300,500 and 700GHz,the detector responsivity is 151.24kV/W,300.52kV/W and 85.9kV/W,and the noise equivalent power is 132 pW/(?),105 pW/(?)and 147pW/(?),respectively.