Introduce public antenna property and setter, checks if input is of type MicrowaveAntenna.

src/tetrax/core/experimental_setup.py

@@ -34,6 +34,17 @@ class ExperimentalSetup:
             else:
                 print("You are trying to set an external field which does not match the shape of the mesh.")
 
+    @property
+    def antenna(self):
+        return self.antenna
+
+    @antenna.setter
+    def antenna(self, value):
+        if isinstance(value, MicrowaveAntenna):
+            self._antenna = value
+        else:
+            raise ValueError(f'Input {value} is not of type "MicrowaveAntenna"')
+
 
     def show(self, comp="vec", scale=5, show_antenna=True):
         plot = k3d.plot()