S-Parameter Plotter
Load Touchstone files (.s1p through .s9p) in the left panel, select which files and parameters to plot, then click Plot. Supports MA, RI and DB formats.
About the S-Parameter Plotter
S-parameters (scattering parameters) describe how RF signals are transmitted and reflected at the ports of a network. They are measured by a Vector Network Analyser (VNA) and stored in Touchstone file format (.s2p for two-port, .s7p for seven-port, etc.). This plotter lets you upload any Touchstone file and instantly visualise all S-parameters without needing VNA software or a simulation tool.
What Each Parameter Shows
S11 is the input reflection coefficient -- how much signal reflects back from port 1. A low S11 (below -10 dB) means the device is well-matched to 50 ohm. S21 is the forward transmission -- the gain or insertion loss from port 1 to port 2. Positive S21 in dB means gain (amplifier), negative means loss (filter, cable). S12 is reverse isolation. S22 is the output reflection coefficient. For n-port devices, all Sij parameters are plotted and individually togglable.
Multi-Port Support
This plotter supports Touchstone files from .s1p (one port) up to .s9p (nine port) and beyond. A 7-port file (.s7p) contains 49 S-parameters (S11 through S77). For large port counts, parameters can be toggled on and off individually in the file panel to focus on the ones you need.
Touchstone File Format
The option line in a Touchstone file specifies the frequency unit (Hz, kHz, MHz, GHz), parameter format (MA = magnitude-angle, RI = real-imaginary, DB = dB-angle) and reference impedance (default 50 ohm). This plotter auto-detects all these settings and handles both Touchstone v1 and v2 files.