TP1: V_IN TP2: V_MID TP3: V_OUT R1 D1 R2 C1 L1 L_DELAY Z0=50Ω R3 R4 R5 R6 R7 D2 C2 R8 L2 L3 C3 AM IN OUT

SIG_GEN & TWEAKS

Carrier (fc)40 Hz
Message (fm)3.0 Hz
Mod Index (m)0.80
Env RC Const (τ)0.010
SCROLL

CIRCUIT PATH

COMPONENT EXPLANATION

This is a fully interactive schematic of an Analog AM Demodulator. Hover over any stage on the left to view its technical details and highlight it on the schematic above.

AKSHAT JAIN // Engineering Physics Student

I'm Akshat Jain, studying Engineering Physics at DTU. I'm highly interested in electronics. Feel free to leave me a message or connect via the links on the right.

[TP1] V_IN: Modulated Carrier

  • Carrier: 10kHz | Modulator: 1kHz
  • High-frequency RF signal acts as the base transmission layer.

[STAGE A] Rectifier Front-End

  • Schottky Diode (D1) performs half-wave rectification.
  • R1 acts as a soft-clipping bleed path, preventing abrupt diode cutoff at low amplitudes.

[STAGE K] Pre-Filter & Splitter

  • Passive LC low-pass filter (L1, C1).
  • Damped by R2 to suppress high-frequency RF transients before the delay line. Forms exact "K" topology.

[STAGE S] Microstrip Delay Line

  • Serpentine trace modeled as a lumped delay line (Z0=50Ω).
  • Introduces a fixed propagation delay (Δt) for phase alignment prior to attenuation.

[TP2] V_MID: Envelope Isolation

  • Signal viewed mid-circuit, before final smoothing and full envelope recovery.

[STAGE H] Pi/H-Pad Attenuator

  • Symmetrical resistive Pi-network (R3-R7).
  • Precisely attenuates signal amplitude while maintaining strict 50Ω matching to prevent reflections.

[STAGE A] Primary Envelope Detector

  • The core AM demodulator tracking circuit.
  • D2 acts as a peak series detector.
  • C2 & R8 form a parallel shunt to ground, setting the RC time constant (τ) to track smoothly.

[STAGE T] Final T-Section Filter

  • Passive low-pass T-filter (L2, L3, C3).
  • Heavily attenuates residual 10kHz carrier ripple.

[TP3] V_OUT: Recovered Analog CV

  • The purely extracted 1kHz analog signal, ready for physical synth processing.