Li Xiaohang, Yin Wenfei, Khamas Salam
Department of Electronic and Electrical Engineering, University of Sheffield, Sheffield S10 2TN, UK.
School of Computer Science and Information Engineering, Hefei University of Technology, Hefei 230009, China.
Sensors (Basel). 2021 Jan 28;21(3):876. doi: 10.3390/s21030876.
A slot fed terahertz dielectric resonator antenna driven by an optimized photomixer is proposed, and the interaction of the laser and photomixer is studied. It is demonstrated that in a continuous wave terahertz photomixing scheme, the generated THz power is proportional to the 4th power of the surface electric field of photocondutive layer. Consequently, the optical to THz conversion efficiency of the proposed photomixer has an enhancement factor of 487. This is due to the fact that the surface electric field of the proposed photomixer with a 2D-Photonic Crystal (PhC) superstrate has been improved from 2.1 to 9.9 V/m, which represents a substantial improvement. Moreover, the electrically thick Gallium-Arsenide (GaAs) supporting substrate of the device has been truncated to create a dielectric resonator antenna (DRA) that offers a typical radiation efficiency of more than 90%. By employing a traditional coplanar strip (CPS) biasing network, the matching efficiency has been improved to 24.4%. Therefore, the total efficiency has been considerably improved due to the enhancements in the laser-to-THz conversion, as well as radiation and matching efficiencies. Further, the antenna gain has been improved to 9dBi at the presence of GaAs superstrate. Numerical comparisons show that the proposed antenna can achieve a high gain with relatively smaller dimensions compared with traditional THz antenna with Si lens.
提出了一种由优化的光混频器驱动的缝隙馈电太赫兹介质谐振器天线，并研究了激光与光混频器的相互作用。结果表明，在连续波太赫兹光混频方案中，产生的太赫兹功率与光电导层表面电场的四次方成正比。因此，所提出的光混频器的光到太赫兹转换效率提高了487倍。这是因为具有二维光子晶体（PhC）覆盖层的所提出的光混频器的表面电场已从2.1 V/m提高到9.9 V/m，这是一个显著的改进。此外，该器件的厚电介质砷化镓（GaAs）支撑衬底已被截断以形成介质谐振器天线（DRA），其典型辐射效率超过90%。通过采用传统的共面带状（CPS）偏置网络，匹配效率提高到了24.4%。因此，由于激光到太赫兹转换以及辐射和匹配效率的提高，总效率得到了显著提高。此外，在存在GaAs覆盖层的情况下，天线增益提高到了9 dBi。数值比较表明，与带有硅透镜的传统太赫兹天线相比，所提出的天线能够以相对较小的尺寸实现高增益。
