Abstract: The present invention provides a monolithic superheterodyne detector pixel operable to receive a radio frequency (RF) signal at millimeter wavelength and produce a video output signal with many orders of improved sensitivity when compared with the prior art. This sensitivity improvement is achieved by translating the received RF signal to a intermediate frequency (IF) signal before detection of the video signal. At the lower frequency of the IF signal, monolithic amplification circuitry can be fabricated more easily to provide necessary gain than would be achievable if simple amplification of the RF signal were attempted. Detector pixels constructed in accordance with the invention each contain an antenna for receiving the RF signal. Local oscillator (LO) signal circuitry likewise apply an externally generated LO signal to the pixel. The RF signal and LO signal are then applied by interconnecting conductors to appropriate mixer means to produce the IF signal.