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

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 $f_{0}$ ; 2) precise synchronization of the oscillation phase among elements; 3) cancellation of the radiation at $f_{0}$ , $2f_{0}$ , and $3f_{0}$ ; and 4) efficient radiation and power combining at $4f_{0}$ . The resultant compact design fits into the optimal radiator pitch of $\lambda _{4f_{0}}/2$ (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 2 area and consumes 1.1 W of dc power. The measured total radiated power and the effective isotropically radiated power are 80 $\mu \text{W}$ and 13 dBm, respectively.