configurable Z0 for short/open + additional comment entries

Software/PC_Application/Calibration/calkit.cpp

@@ -181,8 +181,6 @@ Calkit Calkit::fromFile(QString filename)
 
     // set default values for non-editable items (for now)
     c.TRL.Through.Z0 = 50.0;
-    c.SOLT.Short.Z0 = 50.0;
-    c.SOLT.Open.Z0 = 50.0;
     c.SOLT.Through.Z0 = 50.0;
 
     return c;
@@ -201,6 +199,26 @@ void Calkit::edit(std::function<void (void)> done)
 
 class Calkit::SOLT Calkit::toSOLT(double frequency)
 {
+    auto addTransmissionLine = [](complex<double> termination_reflection, double offset_impedance, double offset_delay, double offset_loss, double frequency) -> complex<double> {
+        // nomenclature and formulas from https://loco.lab.asu.edu/loco-memos/edges_reports/report_20130807.pdf
+        auto Gamma_T = termination_reflection;
+        auto f = frequency;
+        auto w = 2.0 * M_PI * frequency;
+        auto f_sqrt = sqrt(f / 1e9);
+
+        auto Z_c = complex<double>(offset_impedance + (offset_loss / (2*w)) * f_sqrt, -(offset_loss / (2*w)) * f_sqrt);
+        auto gamma_l = complex<double>(offset_loss*offset_delay/(2*offset_impedance)*f_sqrt, w*offset_delay+offset_loss*offset_delay/(2*offset_impedance)*f_sqrt);
+
+        auto Z_r = complex<double>(50.0);
+
+        auto Gamma_1 = (Z_c - Z_r) / (Z_c + Z_r);
+
+        auto Gamma_i = (Gamma_1*(1.0-exp(-2.0*gamma_l)-Gamma_1*Gamma_T)+exp(-2.0*gamma_l)*Gamma_T)
+                / (1.0-Gamma_1*(exp(-2.0*gamma_l)*Gamma_1+Gamma_T*(1.0-exp(-2.0*gamma_l))));
+
+        return Gamma_i;
+    };
+
     fillTouchstoneCache();
     class SOLT ref;
     if(SOLT.Load.useMeasurements) {
@@ -216,9 +234,7 @@ class Calkit::SOLT Calkit::toSOLT(double frequency)
         auto imp_L = complex<double>(0, frequency * 2 * M_PI * SOLT.Load.Lseries);
         imp_load += imp_L;
         ref.Load = (imp_load - complex<double>(50.0)) / (imp_load + complex<double>(50.0));
-        // apply phaseshift due to delay
+        ref.Load = addTransmissionLine(ref.Load, SOLT.Load.Z0, SOLT.Load.delay*1e-12, 0, frequency);
-        double load_phaseshift = -2 * M_PI * frequency * 2 * SOLT.Load.delay * 1e-12;
-        ref.Load *= polar<double>(1.0, load_phaseshift);
     }
 
     if(SOLT.Open.useMeasurements) {
@@ -234,12 +250,7 @@ class Calkit::SOLT Calkit::toSOLT(double frequency)
             auto imp_open = complex<double>(0, -1.0 / (frequency * 2 * M_PI * Cfringing));
             ref.Open = (imp_open - complex<double>(50.0)) / (imp_open + complex<double>(50.0));
         }
-        // transform the delay into a phase shift for the given frequency
+        ref.Open = addTransmissionLine(ref.Open, SOLT.Open.Z0, SOLT.Open.delay*1e-12, SOLT.Open.loss*1e9, frequency);
-        double open_phaseshift = -2 * M_PI * frequency * 2 * SOLT.Open.delay * 1e-12;
-        double open_att_db = SOLT.Open.loss * 1e9 * 4.3429 * 2 * SOLT.Open.delay * 1e-12 / SOLT.Open.Z0 * sqrt(frequency / 1e9);
-        double open_att = pow(10.0, -open_att_db / 10.0);
-        auto open_correction = polar<double>(open_att, open_phaseshift);
-        ref.Open *= open_correction;
     }
 
     if(SOLT.Short.useMeasurements) {
@@ -250,12 +261,7 @@ class Calkit::SOLT Calkit::toSOLT(double frequency)
         // convert to impedance
         auto imp_short = complex<double>(0, frequency * 2 * M_PI * Lseries);
         ref.Short =  (imp_short - complex<double>(50.0)) / (imp_short + complex<double>(50.0));
-        // transform the delay into a phase shift for the given frequency
+        ref.Short = addTransmissionLine(ref.Short, SOLT.Short.Z0, SOLT.Short.delay*1e-12, SOLT.Short.loss*1e9, frequency);
-        double short_phaseshift = -2 * M_PI * frequency * 2 * SOLT.Short.delay * 1e-12;
-        double short_att_db = SOLT.Short.loss * 1e9 * 4.3429 * 2 * SOLT.Short.delay * 1e-12 / SOLT.Short.Z0 * sqrt(frequency / 1e9);;
-        double short_att = pow(10.0, -short_att_db / 10.0);
-        auto short_correction = polar<double>(short_att, short_phaseshift);
-        ref.Short *= short_correction;
     }
 
     if(SOLT.Through.useMeasurements) {

Software/PC_Application/Calibration/calkit.h

@@ -14,6 +14,9 @@ public:
     Calkit();
     Calkit& operator=(const Calkit& other)
     {
+        this->manufacturer = other.manufacturer;
+        this->serialnumber = other.serialnumber;
+        this->description = other.description;
         this->SOLT = other.SOLT;
         this->TRL = other.TRL;
         this->startDialogWithSOLT = other.startDialogWithSOLT;
@@ -46,6 +49,8 @@ public:
 private:
     void TransformPathsToRelative(QFileInfo d);
     void TransformPathsToAbsolute(QFileInfo d);
+
+    QString manufacturer, serialnumber, description;
     // SOLT standard definitions
     struct {
         struct {
@@ -94,7 +99,11 @@ private:
         QString name;
         QVariant def;
     };
-    const std::array<JSONDescription, 40> json_descr = {{
+    const std::array<JSONDescription, 43> json_descr = {{
+        {&manufacturer, "Manufacturer", ""},
+        {&serialnumber, "Serialnumber", ""},
+        {&description, "Description", ""},
+
         {&SOLT.Open.Z0, "SOLT/Open/Param/Z0", 50.0},
         {&SOLT.Open.delay, "SOLT/Open/Param/Delay", 0.0},
         {&SOLT.Open.loss, "SOLT/Open/Param/Loss", 0.0},

Software/PC_Application/Calibration/calkitdialog.cpp

@@ -140,6 +140,10 @@ CalkitDialog::~CalkitDialog()
 
 void CalkitDialog::parseEntries()
 {
+    ownKit.manufacturer = ui->manufacturer->text();
+    ownKit.serialnumber = ui->serialnumber->text();
+    ownKit.description = ui->description->toPlainText();
+
     // type
     ownKit.SOLT.Open.useMeasurements = ui->open_measurement->isChecked();
     ownKit.SOLT.Short.useMeasurements = ui->short_measurement->isChecked();
@@ -196,6 +200,10 @@ void CalkitDialog::parseEntries()
 
 void CalkitDialog::updateEntries()
 {
+    ui->manufacturer->setText(ownKit.manufacturer);
+    ui->serialnumber->setText(ownKit.serialnumber);
+    ui->description->setPlainText(ownKit.description);
+
     // Coefficients
     ui->open_Z0->setValueQuiet(ownKit.SOLT.Open.Z0);
     ui->open_delay->setValueQuiet(ownKit.SOLT.Open.delay);

Software/PC_Application/Calibration/calkitdialog.ui

@@ -10,7 +10,7 @@
     <x>0</x>
     <y>0</y>
     <width>1141</width>
-    <height>394</height>
+    <height>602</height>
    </rect>
   </property>
   <property name="sizePolicy">
@@ -28,11 +28,66 @@
   <property name="sizeGripEnabled">
    <bool>false</bool>
   </property>
-  <layout class="QVBoxLayout" name="verticalLayout_9">
+  <layout class="QVBoxLayout" name="verticalLayout_13">
+   <item>
+    <layout class="QFormLayout" name="formLayout_7">
+     <item row="0" column="0">
+      <widget class="QLabel" name="label_27">
+       <property name="text">
+        <string>Manufacturer:</string>
+       </property>
+      </widget>
+     </item>
+     <item row="0" column="1">
+      <widget class="QLineEdit" name="manufacturer"/>
+     </item>
+     <item row="1" column="0">
+      <widget class="QLabel" name="label_31">
+       <property name="text">
+        <string>Serial number:</string>
+       </property>
+      </widget>
+     </item>
+     <item row="1" column="1">
+      <widget class="QLineEdit" name="serialnumber"/>
+     </item>
+    </layout>
+   </item>
+   <item>
+    <layout class="QHBoxLayout" name="horizontalLayout_7">
+     <item>
+      <layout class="QVBoxLayout" name="verticalLayout_9">
+       <item>
+        <widget class="QLabel" name="label_28">
+         <property name="text">
+          <string>Description:</string>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <spacer name="verticalSpacer_4">
+         <property name="orientation">
+          <enum>Qt::Vertical</enum>
+         </property>
+         <property name="sizeHint" stdset="0">
+          <size>
+           <width>20</width>
+           <height>40</height>
+          </size>
+         </property>
+        </spacer>
+       </item>
+      </layout>
+     </item>
+     <item>
+      <widget class="QTextEdit" name="description"/>
+     </item>
+    </layout>
+   </item>
    <item>
     <widget class="QTabWidget" name="tabWidget">
      <property name="currentIndex">
-      <number>1</number>
+      <number>0</number>
      </property>
      <widget class="QWidget" name="tab">
       <attribute name="title">
@@ -152,7 +207,7 @@
                <item row="0" column="1">
                 <widget class="SIUnitEdit" name="short_Z0">
                  <property name="enabled">
-                  <bool>false</bool>
+                  <bool>true</bool>
                  </property>
                 </widget>
                </item>
@@ -298,7 +353,7 @@
                <item row="0" column="1">
                 <widget class="SIUnitEdit" name="open_Z0">
                  <property name="enabled">
-                  <bool>false</bool>
+                  <bool>true</bool>
                  </property>
                 </widget>
                </item>
@@ -933,10 +988,10 @@
   </connection>
  </connections>
  <buttongroups>
-  <buttongroup name="TRL_Rtype"/>
+  <buttongroup name="ThroughType"/>
-  <buttongroup name="ShortType"/>
   <buttongroup name="LoadType"/>
   <buttongroup name="OpenType"/>
-  <buttongroup name="ThroughType"/>
+  <buttongroup name="ShortType"/>
+  <buttongroup name="TRL_Rtype"/>
  </buttongroups>
 </ui>