Allow Touchstone files for calibration (NanoVNA-Saver#727)

* Update Calibration.py
* Update Touchstone.py
* Update CalibrationSettings.py

src/NanoVNASaver/Calibration.py

@@ -368,8 +368,12 @@ def calc_corrections(self):
         logger.debug("Calibration correctly calculated.")
 
     def gamma_short(self, freq: int) -> complex:
-        if self.cal_element.short_is_ideal:
+        if self.cal_element.short_state == "IDEAL":
             return IDEAL_SHORT
+        if self.cal_element.short_state == "FILE":
+            self.cal_element.short_touchstone.gen_interpolation_s11()
+            dp = self.cal_element.short_touchstone.s_freq("11", freq)
+            return complex(dp.re, dp.im)
         logger.debug("Using short calibration set values.")
         cal_element = self.cal_element
         Zsp = complex(
@@ -394,8 +398,12 @@ def gamma_short(self, freq: int) -> complex:
         )
 
     def gamma_open(self, freq: int) -> complex:
-        if self.cal_element.open_is_ideal:
+        if self.cal_element.open_state == "IDEAL":
             return IDEAL_OPEN
+        if self.cal_element.open_state == "FILE":
+            self.cal_element.open_touchstone.gen_interpolation_s11()
+            dp = self.cal_element.open_touchstone.s_freq("11", freq)
+            return complex(dp.re, dp.im)
         logger.debug("Using open calibration set values.")
         cal_element = self.cal_element
         Zop = complex(
@@ -415,8 +423,12 @@ def gamma_open(self, freq: int) -> complex:
         )
 
     def gamma_load(self, freq: int) -> complex:
-        if self.cal_element.load_is_ideal:
+        if self.cal_element.load_state == "IDEAL":
             return IDEAL_LOAD
+        if self.cal_element.load_state == "FILE":
+            self.cal_element.load_touchstone.gen_interpolation_s11()
+            dp = self.cal_element.load_touchstone.s_freq("11", freq)
+            return complex(dp.re, dp.im)
         logger.debug("Using load calibration set values.")
         cal_element = self.cal_element
         Zl = complex(cal_element.load_r, 0.0)
@@ -442,7 +454,7 @@ def gamma_through(self, freq: int) -> complex:
         cal_element = self.cal_element
         return cmath.exp(
             complex(0.0, -2.0 * math.pi * cal_element.through_length * freq)
-        )
+        )    
 
     def gen_interpolation(self):
         (freq, e00, e11, delta_e, e10e01, e30, e22, e10e32) = zip(

src/NanoVNASaver/Touchstone.py

@@ -187,6 +187,34 @@ def gen_interpolation(self):
                     fill_value=(imag[0], imag[-1]),
                 ),
             }
+
+    def gen_interpolation_s11(self):
+        freq = []
+        real = []
+        imag = []
+        for dp in self.s("11"):
+            freq.append(dp.freq)
+            real.append(dp.re)
+            imag.append(dp.im)
+
+        self._interp["11"] = {
+            "real": interp1d(
+                freq,
+                real,
+                kind="slinear",
+                bounds_error=False,
+                fill_value=(real[0], real[-1]),
+            ),
+            "imag": interp1d(
+                freq,
+                imag,
+                kind="slinear",
+                bounds_error=False,
+                fill_value=(imag[0], imag[-1]),
+            ),
+        }
+
+
 
     def _parse_comments(self, fp) -> str:
         for line in fp:

src/NanoVNASaver/Windows/CalibrationSettings.py

@@ -25,6 +25,8 @@
 from NanoVNASaver.Calibration import Calibration
 from NanoVNASaver.Settings.Sweep import SweepMode
 from NanoVNASaver.Windows.Defaults import make_scrollable
+from NanoVNASaver.Touchstone import Touchstone
+
 
 logger = logging.getLogger(__name__)
 
@@ -165,11 +167,40 @@ def __init__(self, app: QtWidgets.QWidget):
 
         cal_standard_box = QtWidgets.QGroupBox("Calibration standards")
         cal_standard_layout = QtWidgets.QFormLayout(cal_standard_box)
-        self.use_ideal_values = QtWidgets.QCheckBox("Use ideal values")
-        self.use_ideal_values.setChecked(True)
-        self.use_ideal_values.stateChanged.connect(self.idealCheckboxChanged)
-        cal_standard_layout.addRow(self.use_ideal_values)
+        self.use_ideal_values = QtWidgets.QRadioButton("Use ideal values")
+        self.use_s1p_files = QtWidgets.QRadioButton("Use s1p files")
+        self.use_coefficients = QtWidgets.QRadioButton("Use coefficients")
 
+
+        self.use_ideal_values.setChecked(True)
+        self.radio_group = QtWidgets.QButtonGroup(self)
+        self.radio_group.addButton(self.use_ideal_values)
+        self.radio_group.addButton(self.use_s1p_files)
+        self.radio_group.addButton(self.use_coefficients)
+        self.radio_group.buttonClicked.connect(self.calStandardChanged)
+
+        self.radio_layout = QtWidgets.QHBoxLayout()
+        self.radio_layout.addWidget(self.use_ideal_values)
+        self.radio_layout.addWidget(self.use_s1p_files)
+        self.radio_layout.addWidget(self.use_coefficients)
+        cal_standard_layout.addRow(self.radio_layout)
+
+
+        self.file_button_short = QtWidgets.QPushButton("Short S1P file")
+        self.file_button_open = QtWidgets.QPushButton("Open S1P file")
+        self.file_button_load = QtWidgets.QPushButton("Load S1P file")
+        self.file_button_short.setEnabled(False)
+        self.file_button_open.setEnabled(False)
+        self.file_button_load.setEnabled(False)
+
+        cal_standard_layout.addRow(self.file_button_short)
+        cal_standard_layout.addRow(self.file_button_open)
+        cal_standard_layout.addRow(self.file_button_load)
+
+        self.file_button_open.clicked.connect(self.select_file_open)
+        self.file_button_short.clicked.connect(self.select_file_short)
+        self.file_button_load.clicked.connect(self.select_file_load)
+
         self.cal_short_box = QtWidgets.QGroupBox("Short")
         cal_short_form = QtWidgets.QFormLayout(self.cal_short_box)
         self.cal_short_box.setDisabled(True)
@@ -188,7 +219,8 @@ def __init__(self, app: QtWidgets.QWidget):
         cal_short_form.addRow("L2 (H(e-33))", self.short_l2_input)
         cal_short_form.addRow("L3 (H(e-42))", self.short_l3_input)
         cal_short_form.addRow("Offset Delay (ps)", self.short_length)
-
+
+
         self.cal_open_box = QtWidgets.QGroupBox("Open")
         cal_open_form = QtWidgets.QFormLayout(self.cal_open_box)
         self.cal_open_box.setDisabled(True)
@@ -208,6 +240,7 @@ def __init__(self, app: QtWidgets.QWidget):
         cal_open_form.addRow("C3 (F(e-45))", self.open_c3_input)
         cal_open_form.addRow("Offset Delay (ps)", self.open_length)
 
+
         self.cal_load_box = QtWidgets.QGroupBox("Load")
         cal_load_form = QtWidgets.QFormLayout(self.cal_load_box)
         self.cal_load_box.setDisabled(True)
@@ -225,6 +258,8 @@ def __init__(self, app: QtWidgets.QWidget):
         cal_load_form.addRow("Capacitance (F(e-15))", self.load_capacitance)
         cal_load_form.addRow("Offset Delay (ps)", self.load_length)
 
+
+
         self.cal_through_box = QtWidgets.QGroupBox("Through")
         cal_through_form = QtWidgets.QFormLayout(self.cal_through_box)
         self.cal_through_box.setDisabled(True)
@@ -264,6 +299,9 @@ def __init__(self, app: QtWidgets.QWidget):
 
         cal_standard_layout.addWidget(self.cal_standard_save_box)
         right_layout.addWidget(cal_standard_box)
+        self.open_touchstone = None
+        self.short_touchstone = None
+        self.load_touchstone = None
 
     def checkExpertUser(self):
         if not self.app.settings.value("ExpertCalibrationUser", False, bool):
@@ -499,6 +537,9 @@ def reset(self):
         self.calibration_status_label.setText("Device calibration")
         self.calibration_source_label.setText("Device")
         self.notes_textedit.clear()
+        self.short_touchstone = None
+        self.open_touchstone = None
+        self.load_touchstone = None
 
         if len(self.app.worker.rawData11) > 0:
             # There's raw data, so we can get corrected data
@@ -546,16 +587,16 @@ def calculate(self):
             )
             return
 
-        cal_element.short_is_ideal = True
-        cal_element.open_is_ideal = True
-        cal_element.load_is_ideal = True
+        cal_element.short_state = "IDEAL"
+        cal_element.open_state = "IDEAL"
+        cal_element.load_state = "IDEAL"
         cal_element.through_is_ideal = True
 
         # TODO: all ideal or not?
-        if not self.use_ideal_values.isChecked():
-            cal_element.short_is_ideal = False
-            cal_element.open_is_ideal = False
-            cal_element.load_is_ideal = False
+        if self.radio_group.checkedButton() == self.use_coefficients:
+            cal_element.short_state = "COEFF"
+            cal_element.open_state = "COEFF"
+            cal_element.load_state = "COEFF"
             cal_element.through_is_ideal = False
 
             # We are using custom calibration standards
@@ -606,6 +647,20 @@ def calculate(self):
             cal_element.through_length = (
                 getFloatValue(self.through_length.text()) / 1.0e12
             )
+        elif self.radio_group.checkedButton() == self.use_s1p_files:
+            if (self.short_touchstone is not None):
+                cal_element.short_state = "FILE"
+                cal_element.short_touchstone = self.short_touchstone
+            if (self.open_touchstone is not None):
+                cal_element.open_state = "FILE"
+                cal_element.open_touchstone = self.open_touchstone
+            if (self.load_touchstone is not None):
+                cal_element.load_state = "FILE"
+                cal_element.load_touchstone = self.load_touchstone
+            cal_element.through_is_ideal = False
+            cal_element.through_length = (
+                getFloatValue(self.through_length.text()) / 1.0e12
+            )
 
         logger.debug("Attempting calibration calculation.")
         try:
@@ -704,15 +759,34 @@ def saveCalibration(self):
             logger.error("Calibration save failed!")
             self.app.showError("Calibration save failed.")
 
-    def idealCheckboxChanged(self):
-        self.cal_short_box.setDisabled(self.use_ideal_values.isChecked())
-        self.cal_open_box.setDisabled(self.use_ideal_values.isChecked())
-        self.cal_load_box.setDisabled(self.use_ideal_values.isChecked())
-        self.cal_through_box.setDisabled(self.use_ideal_values.isChecked())
-        self.cal_standard_save_box.setDisabled(
-            self.use_ideal_values.isChecked()
-        )
-
+    def calStandardChanged(self, button):
+        if button == self.use_ideal_values:
+            self.cal_short_box.setDisabled(True)
+            self.cal_open_box.setDisabled(True)
+            self.cal_load_box.setDisabled(True)
+            self.cal_through_box.setDisabled(True)
+            self.cal_standard_save_box.setDisabled(True)
+            self.file_button_short.setDisabled(True)
+            self.file_button_open.setDisabled(True)
+            self.file_button_load.setDisabled(True)
+        elif button == self.use_s1p_files:
+            self.cal_short_box.setDisabled(True)
+            self.cal_open_box.setDisabled(True)
+            self.cal_load_box.setDisabled(True)
+            self.cal_through_box.setDisabled(False)
+            self.cal_standard_save_box.setDisabled(True)
+            self.file_button_short.setDisabled(False)
+            self.file_button_open.setDisabled(False)
+            self.file_button_load.setDisabled(False)
+        elif button == self.use_coefficients:
+            self.cal_short_box.setDisabled(False)
+            self.cal_open_box.setDisabled(False)
+            self.cal_load_box.setDisabled(False)
+            self.cal_through_box.setDisabled(False)
+            self.cal_standard_save_box.setDisabled(False)
+            self.file_button_short.setDisabled(True)
+            self.file_button_open.setDisabled(True)
+            self.file_button_load.setDisabled(True)            
     def automaticCalibration(self):
         self.btn_automatic.setDisabled(True)
         introduction = QtWidgets.QMessageBox(
@@ -970,3 +1044,20 @@ def automaticCalibrationStep(self):
                 self.automaticCalibrationStep
             )
             return
+    def select_file_open(self):
+        filename, _ = QtWidgets.QFileDialog.getOpenFileName(self, "Select Open S1P", "", "Touchstone Files (*.s1p)")
+        if filename != "":
+            self.open_touchstone = Touchstone(filename)
+            self.open_touchstone.load()            
+
+    def select_file_short(self):
+        filename, _ = QtWidgets.QFileDialog.getOpenFileName(self, "Select Short S1P", "", "Touchstone Files (*.s1p)")
+        if filename != "":
+            self.short_touchstone = Touchstone(filename)
+            self.short_touchstone.load()
+
+    def select_file_load(self):
+        filename, _ = QtWidgets.QFileDialog.getOpenFileName(self, "Select Load S1P", "", "Touchstone Files (*.s1p)")
+        if filename != "":
+            self.load_touchstone = Touchstone(filename)
+            self.load_touchstone.load()