A tuned antenna-coupled infrared detector is made possible by application of a bias voltage in the range of a few hundred millivolts. The use of first and second antenna arms connected to the detector makes possible polarization tuning which eliminates the need for bulk-optical polarization filters. An alternative tuned detector is one in which the antenna is frequency tuned by a capacitative device to make the detector particularly responsive to 8 um to 12 um infrared radiation. When integrated into focal plane arrays, these detectors can be used in remote-sensing systems to facilitate enhanced image recognition, feature extraction and image-clutter removal. One preferred version of the polarization tuned antenna has longitudinal metal antenna arms extending outward from an infrared(IR) sensor in a spiral pattern, with polarization tuning devices connected between the antenna arms, and a voltage for controlling the polarization tuning devices, wherein the polarization tuning devices enable real-time control of current distribution in the arms. For the frequency tuned sensors, the embodiment is preferably a microstrip antenna coupled to a bolometer wherein the sensor has a tunable response accomplished by use of a single substrate voltage on a separate capacitative device. The infrared(IR) sensors can be tunnel diodes, schottky diodes, photovoltaics, photoconductors, bolometers and pyroelectrics. Application areas can include earth-resource mapping, pollution monitoring, and general surveillance.
Wavelength-tunable coupled antenna uncooled infrared (IR) sensor