A 600-GHz Harmonic Injection-Locked Receiver Array Using Interleaved Modulation in 28-nm CMOS

Harmonic injection-locked receivers have demonstrated state-of-the-art above-
$f_{\mathrm {max}}$
sensitivity in CMOS. This high sensitivity makes them an excellent choice for low power, compact THz imaging applications. Imaging solutions typically employ arrays instead of single pixels to avoid mechanical movement and reduce the imaging time. Harmonic injection-locked receivers have a low power consumption and area, which favors the deployment of this topology in an array, but a specific additional consideration is required. When expanding from a single pixel into an array, mutual disturbance between the on-chip oscillators has to be avoided to maintain the image quality when operating pixels simultaneously. In this letter, this unwanted coupling is studied and interleaved modulation techniques to mitigate it are explored.