Broadband beamforming of terahertz pulses with a single-chip 4×2 array in silicon

In this paper, a single-chip impulse antenna array is presented that performs spatial combining of picosecond impulses radiated from 8 elements. A new broadband beamforming architecture is introduced that controls the timing of impulses radiated from each antenna by delaying a trigger signal, with resolution steps of 300fsec. This method eliminates the distortive and narrowband effects of delay blocks in conventional phased arrays by separating the delay path from the information path. Frequency domain measurements are performed up to 1.03THz and array directivities of 22dBi at 0.33THz, 25dBi at 0.57THz, and 27dBi at 0.75THz are achieved. The 8-element array is fabricated in a 90nm Silicon Germanium BiCMOS process technology.