Design Of CMOS Terahertz Detector For Arbitrarily Polarized And Multi-frequency Detection

Terahertz（THz）waves have the spectral characteristics of both microwave and infrared bands,and have broad application prospects in security imaging,astronomical observation,biomedicine,and autonomous driving.THz detectors are the core components of THz technology.Integrated circuit-based CMOS THz detectors have the advantages of low cost,high integration,and room temperature detection,and show great potential in the application of THz detection and imaging systems.Research and development of CMOS THz detectors with high responsivity（R_V）,low noise equivalent power（NEP）,large bandwidth,and low polarization selectivity are the main development directions in this field.This paper designs and prepares CMOS THz detectors for arbitrarily polarized and multi-band detection based on standard integrated circuit technology,and analyzes the photoelectric performance of related detectors.The obtained arbitrarily polarized THz detector has a circular polarization axis ratio of 1.1 d B,and the obtained multi-frequency detector can produce responses in three frequency bands within 50-700 GHz.The specific research results are as follows:1.An arbitrarily polarized THz detector is designed and fabricated based on standard integrated circuit technology.Using mutually perpendicular dipole optical antennas,with 250 GHz as the frequency center,a phase-shifting optical antenna structure with a fixed phase difference of 90°was designed,combined with a 45°obliquely placed transistor structure,finally achieved a low THz signal polarization dependence detector unit structure.The experimental results show that in the 210GHz-270 GHz band,the detector can produce a high response to the incident THz signal of any polarization.The best operating frequency is 260 GHz,which corresponds to a maximum R_V of approximately 3.2 k V/W and a minimum NEP of approximately 24.8 p W/Hz^0.5.2.Based on standard integrated circuit technology design and preparation of triple-frequency THz detectors.A dipole multi-frequency antenna is designed,and its sector-shaped receiving surface is composed of multiple sector-shaped rings.The simulation studies the main structural parameters that affect the antenna resonance frequency,and it is found that the larger the radius in the antenna structure,the lower the corresponding antenna resonance frequency.The multi-frequency THz detector with integrated amplifier has been packaged and tested.The measurement results show that the multi-frequency detector can obtain response in 110 GHz,240 GHz and670 GHz,corresponding to the largest R_V of 260.8 k V/W,106.8 k V/W,243.9 k V/W and NEP of 17.1 p W/Hz^0.5,43.2 p W/Hz^0.5 and 18.9 p W/Hz^0.5 respectively.