High-Power Radiation at 1 THz in Silicon: A Fully Scalable Array Using a Multi-Functional Radiating Mesh Structure

Abstract

We introduce a highly scalable architecture of coherent harmonic oscillator array for high-power and narrow-beamwidth radiation in the mid-terahertz (THz) band. The array consists of horizontal and vertical slotlines (i.e., slot mesh) located at the boundaries between oscillator elements. Through such a structure, the following operations are achieved simultaneously: 1) maximum oscillation power at fundamental frequency f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ; 2) precise synchronization of the oscillation phase among elements; 3) cancellation of the radiation at f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> , 2 f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> , and 3 f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ; and 4) efficient radiation and power combining at 4 f0. The resultant compact design fits into the optimal radiator pitch of λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</sub> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> /2 (half wavelength) for the suppression of sidelobes, hence enabling implementation of high-density THz arrays. In particular, an array prototype of 42 coherent radiators (with 91 resonant antennas) at 1 THz is presented using the IHP S13G2 130-nm SiGe process. The chip occupies only 1-mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> area and consumes 1.1 W of dc power. The measured total radiated power and the effective isotropically radiated power are 80 μW and 13 dBm, respectively.