TowerJazz and UCI Demo 94GHz 2x2 Pixel Imager

PR Newswire: TowerJazz announces that researchers at the University of California, Irvine's (UCI's) Nanoscale Communication Integrated Circuits (NCIC) Labs have built a W-band (80-100GHz) 2×2 focal-plane array with record NETD (noise equivalent temperature difference) performance for passive millimeter-wave imaging using TowerJazz's SiGe BiCMOS process (SBC18H2).

This imaging receiver (without antenna) achieves a measured average responsivity and noise equivalent power (NEP) of 285MV/W and 8.1fW/Hz1/2 respectively, across the 86-106GHz bandwidth, which results in a calculated NETD of 0.48K with a 30ms integration time. This represents a 1-2 orders of magnitude improvement in NEP vs. other methods and demonstrations to date, a 4-10x improvement in NETD vs. e.g. 65nm CMOS. With antenna, the system NETD increases to 3K with on-chip antenna due to its low antenna efficiency at W-band. This work demonstrates the highest integration level of any silicon-based system in the 94GHz imaging band and the responsivity achieved is orders of magnitude higher than previous work.

The FPA designed and fabricated using TowerJazz's silicon process incorporates four Dicke-type receivers representing four imaging pixels. Each receiver employs the direct-conversion architecture consisting of an on-chip slot folded dipole antenna, an SPDT switch, a low noise amplifier, a single-balanced mixer, an injection-locked frequency tripler (ILFT), an IF variable gain amplifier, a power detector, an active bandpass filter and a synchronous demodulator. The LO signal is generated by a shared Ka-band PLL and distributed symmetrically to four local ILFTs. The measured LO phase noise is -93dBc/Hz at 1MHz offset from the 96GHz carrier.

Within the millimeter-wave frequency range (30-300GHz), there are propagation windows located near 35, 94, 140, 220GHz, where the atmospheric absorption is relatively low.