CMOS dual-band terahertz on-chip antenna array and detector design

Abstract

In this paper, in response to the limitations of conventional single-pixel terahertz (THz) detectors in detecting a single frequency band and having a low imaging resolution. A dual-band high responsivity (Rv) array detector scheme is proposed. Includes dual-band high-gain on-chip antenna, matching circuit, dual-band self-mixing receiver circuit and integrated voltage amplifier. The proposed on-chip antenna uses a multi-loop nested design based on the octagonal antenna to realize the dual-band high gain characteristics. In addition, the use of ‘cross-loop’ metal modules as ground plane isolation effectively reduces the electromagnetic interference between the units in the array and ensures the stable operation of the detector array. The matching circuit realizes the maximum power transmission of THz signals between the antenna and the receiving circuit, improved detector Rv. The integrated two-stage voltage amplifier is able to effectively amplify the signal output from the receiver circuit to further increase the detector response voltage. The designed detector is fabricated using 0.18 μm CMOS process. Simulation results show that the antenna has a maximum gain of 5.23 dBi in the 0.37 THz band and 6.77 dBi in the 0.76 THz band. The detector can detect in both 0.37 and 0.76 THz bands. The experimental results demonstrate that the THz detector array, configured according to the proposed design scheme, exhibits a maximum Rv of 55 kV W−1 and a minimum noise equivalent power of 52.4 pW Hz1/2 at a single detector pixel operating within the 0.37 THz band.