On-Chip Terahertz Detector Designed with Inset-Feed Rectangular Patch Antenna and Catadioptric Lens

Fan Zhao,Sheng Xie,Luhong Mao,Weilian Guo,Clarence Augustine T H Tee

doi:10.3390/electronics9061049

Abstract

This study proposes an on-chip terahertz (THz) detector designed with on-chip inset-feed rectangular patch antenna and catadioptric lens. The detector incorporates a dual antenna and dual NMOSFET structure. Radiation efficiency of the antenna reached 89.4% with 6.89 dB gain by optimizing the antenna inset-feed and micro-strip line sizes. Simulated impedance was 85.55 − j19.81 Ω, and the impedance of the antenna with the ZEONEX horn-like catadioptric lens was 117.03 − j20.28 Ω. Maximum analyzed gain of two on-chip antennas with catadioptric lens was 17.14 dB resonating at 267 GHz. Maximum experimental gain of two on-chip patch antennas was 4.5 dB at 260 GHz, increasing to 10.67 dB at 250 GHz with the catadioptric lens. The proposed on-chip rectangular inset-feed patch antenna has a simple structure, compatible with CMOS processing and easily implemented. The horn-like catadioptric lens was integrated into the front end of the detector chip and hence is easily molded and manufactured, and it effectively reduced terahertz power absorption by the chip substrate. This greatly improved the detector responsivity and provided very high gain. Corresponding detector voltage responsivity with and without the lens was 95.67 kV/W with NEP = 12.8 pW/Hz0.5 at 250 GHz, and 19.2 kV/W with NEP = 67.2 pW/Hz0.5 at 260 GHz, respectively.

Highlights

Terahertz (THz) detectors have been recently employed to assist security aspects for high-speed data communication, spectroscopy, concealed weapon detection, short-range radar, aviation assistance, cancer detection, and many more applications [1,2,3,4]
This study proposes an on-chip terahertz detector with on-chip rectangular inset-feed patch antennas that was implemented using a United Microelectronics Corporation (UMC) 0.18 μm standard
The antenna output port is connected to the matching network, and the network is connected to an NMOSFET (TeraFET) for improved power transfer efficiency

Summary

Introduction

Terahertz (THz) detectors have been recently employed to assist security aspects for high-speed data communication, spectroscopy, concealed weapon detection, short-range radar, aviation assistance, cancer detection, and many more applications [1,2,3,4]. Designing an on-chip antenna in the terahertz band is somewhat difficult, partly because the system’s dynamic range and transmission distance between the THz wave source and detector are influenced by antenna gain. Rectangular antennas are the most common on-chip design, leveraging simple structure and being compatible with standard CMOS processing [18,19]. The DRA was 290–310 μm wide and 390–410 μm long, considerably larger than the traditional rectangular patch antenna, and provided measured 6.7 dB maximum gain at 327 GHz. there is considerable ongoing research to improve THz detector antenna gain. This study proposes an on-chip terahertz detector with on-chip rectangular inset-feed patch antennas that was implemented using a United Microelectronics Corporation (UMC) 0.18 μm standard.

On-Chip THz Antenna

Terahertz Detector Circuit

Catadioptric Horn-Like Lens

Terahertz Chip Measurements

Conclusions