A wide dynamic range square-law diode detector (for radioastronomy)

Semiconductor square-law diode detectors are frequently used in radio astronomy to recover signals immersed in the system noise. Their use is commonly restricted to narrow dynamic ranges of very low signal levels where the square-law is valid. A circuit based on operational amplifiers is proposed that would minimize temperature-drift effects within a dynamic range greater than 30 dB, with an efficiency 600 timer greater than the simple high-impedance unbiased detector. Using square-law detector theory, optimum performance is determined for a detector driving source impedance of about 14% of the dynamic resistance.<
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