Engineering topics
Publications and source records attributed to Arams, F. R..
Wideband heterodyne receiver provides detection and demodulation of incident frequency modulated laser signal; search and acquisition circuitry to align two stations; tracking circuitry to maintain spatial alignment; and laser frequency monitor to frequency lock the transmit and local oscillator lasers.
Description of a high-sensitivity wide-bandwidth 10.6-micron heterodyne receiver for space and ground operational use. The receiver includes a cooled HgCdTe infrared mixer diode, a conical scanner for spatial tracking, an acquisition channel for spatial search and station alignment, and an automatic frequency-control channel to maintain a fixed laser frequency offset. The infrared mixer is designed to provide nearly quantum-noise-limited operation over an extended range of mixer temperature, bias voltage, and intermediate frequency. The resultant experimental receiver has a measured noise equivalent power of less than 10 to the minus 19th W/Hz over the 15- to 40-MHz i.f. band for mixer temperatures from 85 to 115 K, and less than 2 x 10 to the minus 19th W/Hz up to 140 K. Mixer 3-dB cutoff frequencies as high as 420 MHz were measured at a mixer temperature of 125 K. An analysis and engineering equations are given for receiver noise components, noise equivalent power, available mixer conversion gain, mixer transducer gain, and quantum-noise factor in terms of such factors as mixer parameters, quantum efficiency, mixer temperature, dynamic conductance, bias voltage, local oscillator power, and i.f. amplifier characteristics.
IR photodiode heterodyne detection, deriving noise equivalent power, conversion gain, frequency response, local oscillator power and IF amplifier noise factor
Heterodyne detection in photoconductors, discussing engineering design for high sensitivity in IR
Broadband power detector assembly measures electromagnetic radiation in the 50 to 30,000 GHz band. The assembly includes a matched pair of detectors which incorporate thin-film radiation absorbers. The detector is effective with either coherent or incoherent radiation.