Fix impedance renormalization and honor new reference impedance for t…

…races
chenminacm · Mar 1, 2024 · 3588729 · 3588729
1 parent 542b07f
commit 3588729
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Showing 5 changed files with 20 additions and 9 deletions.
diff --git a/Software/PC_Application/LibreVNA-GUI/Traces/trace.cpp b/Software/PC_Application/LibreVNA-GUI/Traces/trace.cpp
@@ -151,7 +151,7 @@ void Trace::addData(const Trace::Data &d, const DeviceDriver::SASettings &s, int
     addData(d, domain, 50.0, index);
 }
 
-void Trace::addDeembeddingData(const Trace::Data &d, int index)
+void Trace::addDeembeddingData(const Trace::Data &d, double reference_impedance, int index)
 {
     bool wasAvailable = deembeddingAvailable();
     if(index >= 0) {
@@ -179,6 +179,7 @@ void Trace::addDeembeddingData(const Trace::Data &d, int index)
             deembeddingData.insert(lower, d);
         }
     }
+    deembedded_reference_impedance = reference_impedance;
     if(deembeddingActive) {
         emit outputSamplesChanged(index, index + 1);
     }
@@ -687,7 +688,11 @@ void Trace::setModel(TraceModel *model)
 
 double Trace::getReferenceImpedance() const
 {
-    return reference_impedance;
+    if(deembeddingActive) {
+        return deembedded_reference_impedance;
+    } else {
+        return reference_impedance;
+    }
 }
 
 const std::vector<Trace::MathInfo>& Trace::getMathOperations() const
@@ -1316,6 +1321,10 @@ bool Trace::deembeddingAvailable()
 
 void Trace::setDeembeddingActive(bool active)
 {
+    if(active == deembeddingActive) {
+        // no change
+        return;
+    }
     deembeddingActive = active;
     if(deembeddingAvailable()) {
         if(active) {
@@ -1330,6 +1339,7 @@ void Trace::setDeembeddingActive(bool active)
 void Trace::clearDeembedding()
 {
     deembeddingData.clear();
+    setDeembeddingActive(false);
     deembeddingChanged();
 }
 

diff --git a/Software/PC_Application/LibreVNA-GUI/Traces/trace.h b/Software/PC_Application/LibreVNA-GUI/Traces/trace.h
@@ -46,7 +46,7 @@ class Trace : public TraceMath
     void clear(bool force = false);
     void addData(const Data& d, DataType domain, double reference_impedance = 50.0, int index = -1);
     void addData(const Data& d, const DeviceDriver::SASettings &s, int index = -1);
-    void addDeembeddingData(const Data& d, int index = -1);
+    void addDeembeddingData(const Data& d, double reference_impedance = 50.0, int index = -1);
     void setName(QString name);
     void setVelocityFactor(double v);
     void fillFromTouchstone(Touchstone &t, unsigned int parameter);
@@ -288,6 +288,7 @@ private slots:
     // de-embedding variables
     std::vector<Data> deembeddingData;
     bool deembeddingActive;
+    double deembedded_reference_impedance;
 
     std::vector<MathInfo> mathOps;
     TraceMath *lastMath;

diff --git a/Software/PC_Application/LibreVNA-GUI/Traces/tracemodel.cpp b/Software/PC_Application/LibreVNA-GUI/Traces/tracemodel.cpp
@@ -314,7 +314,7 @@ void TraceModel::addVNAData(const DeviceDriver::VNAMeasurement& d, TraceMath::Da
             if(!deembedded) {
                 t->addData(td, datatype, d.Z0, index);
             } else {
-                t->addDeembeddingData(td, index);
+                t->addDeembeddingData(td, d.Z0, index);
             }
         }
     }

diff --git a/Software/PC_Application/LibreVNA-GUI/VNA/Deembedding/impedancerenormalization.cpp b/Software/PC_Application/LibreVNA-GUI/VNA/Deembedding/impedancerenormalization.cpp
@@ -46,7 +46,7 @@ void ImpedanceRenormalization::transformDatapoint(DeviceDriver::VNAMeasurement &
     for(auto i=1;i<=ports;i++) {
         auto S11name = "S"+QString::number(i)+QString::number(i);
         auto S11 = p.measurements[S11name];
-        transformed[S11name] = Sparam(ABCDparam(Sparam(S11, 0.0, 0.0, 1.0), p.Z0), impedance).m11;
+        transformed[S11name] = Sparam(ABCDparam(Sparam(S11, 0.1, 0.1, 1.0), p.Z0), impedance).m11;
         for(auto j=i+1;j<=ports;j++) {
                 auto S12name = "S"+QString::number(i)+QString::number(j);
                 auto S21name = "S"+QString::number(j)+QString::number(i);

diff --git a/Software/PC_Application/LibreVNA-GUI/VNA/vna.cpp b/Software/PC_Application/LibreVNA-GUI/VNA/vna.cpp
@@ -94,10 +94,6 @@ VNA::VNA(AppWindow *window, QString name)
 
     connect(calLoad, &QAction::triggered, [=](){
         LoadCalibration();
-        if(window->getDevice() && !cal.validForDevice(window->getDevice()->getSerial())) {
-            InformationBox::ShowMessage("Invalid calibration", "The selected calibration was created for a different device. You can still load it but the resulting "
-                                        "data likely isn't useful.");
-        }
         if(cal.getCaltype().type != Calibration::Type::None) {
             if(InformationBox::AskQuestion("Adjust span?", "Do you want to adjust the span to match the loaded calibration file?", false)) {
                 SpanMatchCal();
@@ -510,6 +506,10 @@ VNA::VNA(AppWindow *window, QString name)
         calApplyToTraces->setEnabled(true);
         bMatchCal->setEnabled(true);
         saveCal->setEnabled(true);
+        if(window->getDevice() && !cal.validForDevice(window->getDevice()->getSerial())) {
+            InformationBox::ShowMessage("Invalid calibration", "The selected calibration was created for a different device. You can still load it but the resulting "
+                                                               "data likely isn't useful.");
+        }
     });
 
     tb_cal->addWidget(cbType);