High-Sensitivity RF Choke-Enhanced Dipole Antenna-Coupled Nb5N6 THz Detector

Chengtao Jiang,Xiaoqing Jia,Lin Kang,Xuecou Tu,Peiheng Wu,Jian Chen,Chao Wan

doi:10.3389/fphy.2021.768192

Chengtao Jiang, Xiaoqing Jia + Show 5 more

Open Access

https://doi.org/10.3389/fphy.2021.768192

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Abstract

In this study, we demonstrate an Nb5N6 terahertz (THz) detector with radio frequency (RF) choke-enhanced dipole antenna structure for 0.3 THz detection. The maximum electric field intensity of 218 V/m is obtained by optimizing the parameters of the dipole antenna with RF choke. Compared to a dipole antenna without RF choke, the electric field intensity of that with RF choke is improved by 2.6 times. The RF choke-enhanced dipole antenna-coupled Nb5N6 THz detector is fabricated and characterized. The measured maximum responsivity of the detector is 1100 V/W at 0.308 THz, and the corresponding noise equivalent power (NEP) is 6.4 × 10–12 W/Hz1/2. The measured response time of the Nb5N6 THz detector is as low as 8.46 μs. Furthermore, the Nb5N6 THz detector is applied to a homemade THz transmission imaging system for demonstrating its performance. The THz imaging results of a blade and access card show that the contrast of the blade image is sharp and the components hidden within the access card are clearly visible. This indicates that the Nb5N6 THz detector can be used in THz imaging, particularly in THz active imaging, which will have greater application prospects.

Highlights

In recent years, with the development of science and technology, the terahertz (THz) waves have attracted worldwide interest
We applied the Nb5N6 THz detector to a THz transmission imaging system and studied the THz imaging of a blade and access card
These results indicate that the performance of the Nb5N6 microbolometer THz detector integrated with radio frequency (RF) choke-enhanced dipole antenna is good from another perspective and it is sufficient for practical applications

Summary

INTRODUCTION

With the development of science and technology, the terahertz (THz) waves have attracted worldwide interest. It is desirable to combine the advantages of both semiconductors (high TCR for high responsivity) and metals (low resistivity) for the development of fast and sensitive THz detectors. Nb5N6 thin films are promising candidate material for THz bolometer detector at room temperature. Radio frequency (RF) choke structures are often used in the antenna design for improving the antenna performance, such as bandwidth enhancement, multiple band operation, gain enhancement, and radiation pattern shaping [30,31,32,33]. Considering the feature of the RF choke, we designed an RF choke-enhanced dipole antenna to improve the performance of the Nb5N6 THz detector. We applied the Nb5N6 THz detector to a THz transmission imaging system and studied the THz imaging of a blade and access card

Design and Fabrication

CONCLUSION

DATA AVAILABILITY STATEMENT