Performance Bounds for a Maxima-Sampling Envelope Detector

Envelope detectors in automatic gain control systems must achieve both low tracking latency and low output ripple for feedback stability. Conventional non-sampled envelope detectors intrinsically trade off latency and ripple. Maxima-sampling envelope detectors (MSEDs), which demodulate by sampling signal peaks, circumvent this latency-ripple trade-off, enabling control loops that remain stable over several frequency decades. However, MSED nonlinearity causes an intricate, previously uncharacterized interplay between input spectral properties and performance. This work analytically derives and numerically verifies input-dependent performance bounds for MSEDs. By formulating practical “rules-of-thumb” for mixed-signal circuit designers, we pave the way for the broader adoption of MSEDs.