A 0.34-THz Wideband Wide-Angle 2-D Steering Phased Array in 0.13- μm SiGe BiCMOS

Abstract

In this paper, a 0.34-THz 2 × 2 phased array integrated circuit is presented, which demonstrates a new approach for implementing phased arrays in the millimeter-wave (mm-wave)/terahertz (THz) spectrum. The circuit structure con- sists of four unit standing wave oscillators. In each cell, fun- damental frequency ( f 0) and odd harmonics are systematically cancelled, while the desired fourth harmonics (4 f0)a r ec o m - bined and radiated by on-chip patch antennas. A phase-shifter- less mechanism is employed based on combining standing and traveling waves to create the required phase shift between the sources for beam steering. The transistors provide negative resis- tance to the circuit and generate the desired fourth harmonics through nonlinearity. Simultaneously, transistors are employed as active variable capacitors for varactor-less frequency tuning. The implemented phased array is capable of independent wideband frequency tuning and 2-D wide-angle beam steering. The circuit is fabricated in a 0 .13-µm SiGe BiCMOS process and is measured to have 52-GHz/15.1% frequency tuning range from 318 to 370 GHz and 128 ◦/53◦ 2-D beam-steering angle. The chip con- sumes 310–640 mW power from a 1.5-V s upply with −6.8-dBm maximum radiated power and minimum −93.1-dBc/Hz phase noise at 10-MHz offset. To the best of our knowledge, this paper has the largest bandwidth among fully integrated THz radiator/phased arrays as well as the widest angle beam steering among fully integrated THz phas