From 0c62b17af7ff4368dcfadd633ae3ffe581638ef8 Mon Sep 17 00:00:00 2001
From: Holger Vogt <holger.vogt@uni-due.de>
Date: Fri, 31 Jul 2026 11:13:12 +0200
Subject: [PATCH] Update on reading, converting, and using an S parameter file.

---
 README.rf | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/README.rf b/README.rf
index 5c715c980..e05c6f846 100644
--- a/README.rf
+++ b/README.rf
@@ -63,8 +63,11 @@ QPAC, QPnoise, and QPXF may be swept over frequency instead of fixed f_in, e.g.
 replace 'qpxf <output node> <f_in>' by 'qpxf <output node> <dec/oct/lin> <Npo> <fstart> <fstop>'
 
 Read S parameters and convert to instance with ports p1 to pN, referenced to ref.
+Command in the .control section:
+pre_snp -native my_touchstone.s2p ; reads a Touchstone file, vector fits and issues a *.nport file
+Instance in the netlist
 N1 p1 p2 ... pN ref mymodel
-.model mymodel nport(file="...")
+.model mymodel nport(file=my_touchstone.nport)
 
 RF two-port stability
 sp ... (generate the S parameters)