Forward Sampler Calculator

Calculates FWD sampler voltage from a current transformer coupler (T1), detector output, MCU DC level, and RF sampler port level (J3) versus RF input. Supports calibration from a real measurement so the model matches your actual board.

Input Parameters

RF Power (W)

Line Impedance (Ω)

T1 Turns Ratio (1 : N)

R1 (Ω)

R2 (Ω)

R3 (Ω)

Use calibration from measured FWD Vpp

Cal power (W)

Measured FWD Vpp (V)

Enter a known measurement (e.g., 100 W and 10 Vpp at the FWD node) to calibrate the effective CT ratio. Uncheck to use the ideal turns value above.

Detector diode drop V_f (V)

Approximate forward drop of D1 (e.g., 0.20–0.50 V for Schottky, 0.70–1.0 V for Diode).

R4 (Ω)

Series from DET node to MCU sense node.

R5 (Ω)

From MCU sense node to ground.

R6 (Ω) – sampler series

Series resistor from FWD to sampler port J3.

R7 (Ω) – sampler load

Shunt to ground at J3. Set near 50 Ω to match the RF line.

Frequency (MHz)

For documentation only; not used directly in the math.

Core Mix / Notes

Results

Enter values and click Compute to see results.