RF Attenuator Design Tool

Overview

The RF Attenuator Design Tool provides synthesis of resistive attenuators in various topologies. All designs include automatic power dissipation calculations for proper component selection.

Attenuator Topologies

The tool supports 10 different attenuator topologies, categorized by matching characteristics and structure:

Topology

Notes

Pi

Matched

Tee

Matched

Bridged-Tee

Matched

Reflection attenuator

Matched

Quarter-wavelength series

Frequency-dependent. Output port unmatched

Quarter-wavelength shunt

Frequency-dependent. Output port unmatched

L-pad 1st series

Very broadband matching

L-pad 1st shunt

Very broadband matching

Series resistor

Two ports unmatched

Shunt resistor

Two ports unmatched

See individual topology documentation for detailed design equations and schematics.

Design Flow

  1. Select topology based on matching requirements and bandwidth

  2. Set attenuation (dB)

  3. Define impedances (Zin, Zout)

  4. Enter input power for dissipation calculation

  5. For quarter-wave: specify frequency and TL implementation

  6. Generate schematic → Tool outputs resistor values and power dissipation

Topology Selection Guide

Requirement

Recommended Topology

Broadband match, simple

Pi or Tee

Widest bandwidth

Reflection (DC to multi-GHz)

Narrowband, low insertion loss

Quarter-Wave

Impedance transformation + attenuation

L-pad

Simplest (no matching)

R-series or R-shunt

References

[1] Vizmuller, P. (1995). RF Design Guide: Systems, Circuits, and Equations. Artech House.

[2] Doherty, W. E., & Joos, R. D. (1998). The PIN Diode Circuit Designer’s Handbook. Microsemi Corp.