An SDLVA (Successive Detection Logarithmic Amplifier) is similar to a DLVA (read about DLVAs here), however, the SDLVA circuit is designed in such a way that it does not need a detector before the logarithmic video amplifier. The SDLVA uses multiple compressive stages of RF gain to emulate the exponential transfer function. The output of each stage is coupled into a linear detector. The typical dynamic range of each detector is approximately 10 dB, which are then summed in a single video amplifier so as to provide a single detected output. The detector operates over a narrower dynamic range, which means that more detectors are needed to cover the same dynamic range.

Compared to DLVAs, SDLVAs can provide very fast pulse rise and settling times because the signal gain and compression takes place in RF circuitry. They are used in radar missile homing systems, radar altimeters and to drive phase detectors or frequency discriminators.

Click here to see SDLVAs from the leading manufacturers.