ABSTRACT
This chapter provides an overview of the passive imaging design and implementation in silicon technologies. Passive millimeter-wave (PMMW) imaging is a method that forms images through the passive detection of natural millimeter-wave radiation from objects. PMMW imaging systems operating near the 94 GHz frequency window provide reasonable balance among capability of currently available silicon technologies, chip size, spatial resolution, and atmospheric attenuation. The chapter covers the basic concept of passive imaging, the miscellaneous applications, the system architecture of a radiometer receiver, the commonly used figure of merit to evaluate passive imaging systems, and the state-of-the-art imaging receivers. Traditionally, radiometers operating at W-band frequency range have been implemented in III-V semiconductor technologies, using multichip systems with module-based level of integration. For the total-power radiometer in May and Rebeiz, a five-stage common-emitter LNA was designed and fabricated. The system comprises a balanced LNA with an embedded Dicke switch, a power detector, and the baseband circuitry.
