An imaging sensor for accepting terahertz signals, including a die made of a dielectric material, one or more antennas for receiving terahertz signals, positioned on top of the die or in an upper layer of the die, each antenna having a CMOS detector electrically coupled to the antenna and positioned in the die below the antenna, a metal shield layer in the die below the antennas and above the CMOS detectors, shielding the CMOS detector from interference signals, a shielding layer under the die comprising a back metal coating and/or a layer of silver epoxy glue for attaching the bottom of the die to a lead frame.