diff --git a/Software/PC_Application/Traces/Math/expression.cpp b/Software/PC_Application/Traces/Math/expression.cpp
index f4a3754..a15e448 100644
--- a/Software/PC_Application/Traces/Math/expression.cpp
+++ b/Software/PC_Application/Traces/Math/expression.cpp
@@ -41,11 +41,13 @@ void Math::Expression::edit()
         exp = ui->expEdit->text();
         expressionChanged();
     });
-    // TODO add power domain
-    if(dataType == DataType::Time) {
-        // select the label explaining the time domain variables (frequency label is the default)
-        ui->stackedWidget->setCurrentIndex(1);
+    switch(dataType) {
+    case DataType::Frequency: ui->stackedWidget->setCurrentIndex(0); break;
+    case DataType::Time: ui->stackedWidget->setCurrentIndex(1); break;
+    case DataType::Power: ui->stackedWidget->setCurrentIndex(2); break;
+    default: break;
     }
+
     d->show();
 }
 
@@ -78,6 +80,7 @@ void Math::Expression::inputSamplesChanged(unsigned int begin, unsigned int end)
         for(unsigned int i=begin;i<end;i++) {
             t = in[i].x;
             f = in[i].x;
+            P = in[i].x;
             w = in[i].x * 2 * M_PI;
             d = root()->timeToDistance(t);
             x = in[i].y;
@@ -103,6 +106,7 @@ void Math::Expression::expressionChanged()
     parser->RemoveVar("d");
     parser->RemoveVar("f");
     parser->RemoveVar("w");
+    parser->RemoveVar("P");
     switch(dataType) {
     case DataType::Time:
         parser->DefineVar("t", Variable(&t));
@@ -112,6 +116,9 @@ void Math::Expression::expressionChanged()
         parser->DefineVar("f", Variable(&f));
         parser->DefineVar("w", Variable(&w));
         break;
+    case DataType::Power:
+        parser->DefineVar("P", Variable(&P));
+        break;
     default:
         break;
     }
diff --git a/Software/PC_Application/Traces/Math/expression.h b/Software/PC_Application/Traces/Math/expression.h
index bf5b02d..39e8b2e 100644
--- a/Software/PC_Application/Traces/Math/expression.h
+++ b/Software/PC_Application/Traces/Math/expression.h
@@ -30,7 +30,7 @@ private slots:
 private:
     QString exp;
     mup::ParserX *parser;
-    mup::Value t, d, f, w, x;
+    mup::Value t, d, f, w, x, P;
 };
 
 }
diff --git a/Software/PC_Application/Traces/Math/expressiondialog.ui b/Software/PC_Application/Traces/Math/expressiondialog.ui
index 5380d30..9210faf 100644
--- a/Software/PC_Application/Traces/Math/expressiondialog.ui
+++ b/Software/PC_Application/Traces/Math/expressiondialog.ui
@@ -44,7 +44,7 @@
        <item>
         <widget class="QLabel" name="label">
          <property name="text">
-          <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;Available variables:&lt;/p&gt;&lt;ul style=&quot;margin-top: 0px; margin-bottom: 0px; margin-left: 0px; margin-right: 0px; -qt-list-indent: 1;&quot;&gt;&lt;li style=&quot; margin-top:12px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;&quot;&gt;x: the S parameter as a (complex) voltage vector. &lt;/li&gt;&lt;li style=&quot; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;&quot;&gt;f: measurement frequency in Hz&lt;/li&gt;&lt;li style=&quot; margin-top:0px; margin-bottom:12px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;&quot;&gt;w: angular measurement frequency (w = 2πf)&lt;/li&gt;&lt;/ul&gt;&lt;p&gt;Examples:&lt;br/&gt;Add 10db to the trace (10db = exp10(10/20) = sqrt(10)):&lt;/p&gt;&lt;ul style=&quot;margin-top: 0px; margin-bottom: 0px; margin-left: 0px; margin-right: 0px; -qt-list-indent: 1;&quot;&gt;&lt;li style=&quot; margin-top:0px; margin-bottom:12px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;&quot;&gt;x * sqrt(10)&lt;/li&gt;&lt;/ul&gt;&lt;p&gt;Clip trace at 0db (0db = exp10(0/20) = 1) while preserving phase:&lt;/p&gt;&lt;ul style=&quot;margin-top: 0px; margin-bottom: 0px; margin-left: 0px; margin-right: 0px; -qt-list-indent: 1;&quot;&gt;&lt;li style=&quot; margin-top:0px; margin-bottom:12px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;&quot;&gt;abs(x) &amp;lt; 1 ? x : exp(i*arg(x))&lt;/li&gt;&lt;/ul&gt;&lt;/body&gt;&lt;/html&gt;</string>
+          <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;Available variables:&lt;/p&gt;&lt;ul style=&quot;margin-top: 0px; margin-bottom: 0px; margin-left: 0px; margin-right: 0px; -qt-list-indent: 1;&quot;&gt;&lt;li style=&quot; margin-top:12px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;&quot;&gt;x: the S parameter as a (complex) voltage vector. &lt;/li&gt;&lt;li style=&quot; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;&quot;&gt;f: measurement frequency in Hz&lt;/li&gt;&lt;li style=&quot; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;&quot;&gt;w: angular measurement frequency (w = 2πf)&lt;/li&gt;&lt;/ul&gt;&lt;p&gt;Examples:&lt;br/&gt;Add 10db to the trace (10db = exp10(10/20) = sqrt(10)):&lt;/p&gt;&lt;ul style=&quot;margin-top: 0px; margin-bottom: 0px; margin-left: 0px; margin-right: 0px; -qt-list-indent: 1;&quot;&gt;&lt;li style=&quot; margin-top:0px; margin-bottom:12px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;&quot;&gt;x * sqrt(10)&lt;/li&gt;&lt;/ul&gt;&lt;p&gt;Clip trace at 0db (0db = exp10(0/20) = 1) while preserving phase:&lt;/p&gt;&lt;ul style=&quot;margin-top: 0px; margin-bottom: 0px; margin-left: 0px; margin-right: 0px; -qt-list-indent: 1;&quot;&gt;&lt;li style=&quot; margin-top:0px; margin-bottom:12px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;&quot;&gt;abs(x) &amp;lt; 1 ? x : exp(i*arg(x))&lt;/li&gt;&lt;/ul&gt;&lt;/body&gt;&lt;/html&gt;</string>
          </property>
         </widget>
        </item>
@@ -61,6 +61,20 @@
        </item>
       </layout>
      </widget>
+     <widget class="QWidget" name="powerPage">
+      <layout class="QVBoxLayout" name="verticalLayout_4">
+       <item>
+        <widget class="QLabel" name="label_4">
+         <property name="text">
+          <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;Available variables:&lt;/p&gt;&lt;ul style=&quot;margin-top: 0px; margin-bottom: 0px; margin-left: 0px; margin-right: 0px; -qt-list-indent: 1;&quot;&gt;&lt;li style=&quot; margin-top:12px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;&quot;&gt;x: the S parameter as a (complex) voltage vector. &lt;/li&gt;&lt;li style=&quot; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;&quot;&gt;P: power of the stimulus signal in dBm&lt;/li&gt;&lt;/ul&gt;&lt;p&gt;Examples:&lt;br/&gt;Add 10db to the trace (10db = exp10(10/20) = sqrt(10)):&lt;/p&gt;&lt;ul style=&quot;margin-top: 0px; margin-bottom: 0px; margin-left: 0px; margin-right: 0px; -qt-list-indent: 1;&quot;&gt;&lt;li style=&quot; margin-top:0px; margin-bottom:12px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;&quot;&gt;x * sqrt(10)&lt;/li&gt;&lt;/ul&gt;&lt;p&gt;Clip trace at 0db (0db = exp10(0/20) = 1) while preserving phase:&lt;/p&gt;&lt;ul style=&quot;margin-top: 0px; margin-bottom: 0px; margin-left: 0px; margin-right: 0px; -qt-list-indent: 1;&quot;&gt;&lt;li style=&quot; margin-top:0px; margin-bottom:12px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;&quot;&gt;abs(x) &amp;lt; 1 ? x : exp(i*arg(x))&lt;/li&gt;&lt;/ul&gt;&lt;/body&gt;&lt;/html&gt;</string>
+         </property>
+         <property name="wordWrap">
+          <bool>true</bool>
+         </property>
+        </widget>
+       </item>
+      </layout>
+     </widget>
     </widget>
    </item>
    <item>