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Non-ionizing terahertz imaging using solid-state integrated electronics has been gaining increasing attention over the past few years. However, there are currently several factors that deter the implementations of fully-integrated imaging systems. Due to the lack of low-noise amplification above f max , the sensitivity of THz pixels on silicon cannot match that of its mm-Wave or light-wave counterparts. This, combined with the focal-plane array configuration adopted by previous sensors, requires exceedingly large power for the illumination sources. Previous works on silicon have demonstrated 1mW radiation [1,3]; but higher power, as well as energy efficiency, are needed for a practical imaging system. In addition, heterodyne imaging scheme was demonstrated to be very effective in enhancing detection sensitivity [4]. Due to the preservation of phase information, it also enables digital beam forming with a small number of receiver units. This however requires phase locking between the THz source and receiver LO with a small frequency offset (IF |
