Format Setting
The Analyzer offers three S-parameter measurement display types:
- rectangular format;
- polar format;
- Smith chart format.
Rectangular Formats
In this format, stimulus values are plotted along X-axis and the measured data are plotted along Y-axis.
To display complex-valued S-parameters along the scalar Y-axis, it must be transformed into a real number. Rectangular formats involve various types of transformation of an S-parameter , where:
- a – real part of S-parameter complex value;
- b – imaginary part of S-parameter complex value.
There are eight types of rectangular formats depending on the measured value plotted along Y-axis (See Table 10).
Table 10: Rectangular formats
| Format Type Description | Label | Data Type (Y-axis) | Measurement Unit (Y-axis) |
|---|---|---|---|
| Logarithmic Magnitude | Log Mag | S-parameter logarithmic magnitude: | Decibel (dB) |
| Voltage Standing Wave Ratio | SWR | Dimensionless value | |
| Phase | Phase | S-parameter phase from –180 to +180: | Degree () |
| Expanded Phase | Expand Phase | S-parameter phase, measurement range expanded to from below –180 to over +180 | Degree () |
| Group Delay | Group Delay | Signal propagation delay within the DUT: | Second (sec.) |
| Linear Magnitude | Lin Mag | S-parameter linear magnitude: | Dimensionless value |
| Real Part | Real | S-parameter real part: | Dimensionless value |
| Imaginary Part | Imag | S-parameter imaginary part: | Dimensionless value |
Polar Format
Polar format represents the measurement results on the polar chart. The distance of a measured point from the graph center corresponds to the magnitude of its value. The counterclockwise angle from the positive horizontal axis corresponds to the phase of the measured value.
The polar graph does not have a frequency axis, so frequency is indicated by markers. There are three types of polar formats corresponding to the data displayed by the marker; the traces remain the same for all the format types.
Table 11: Polar formats
| Format Type Description | Label | Data Displayed by Marker | Measurement Unit (Y-axis) |
|---|---|---|---|
| Linear Magnitude and Phase | Polar (Lin) | S-parameter linear magnitude | Dimensionless value |
| S-parameter phase | Degree () | ||
| Logarithmic Magnitude and Phase | Polar (Log) | S-parameter logarithmic magnitude | Decibel (dB) |
| S-parameter phase | Degree () | ||
| Real and Imaginary Parts | Polar (Re/Im) | S-parameter real part | Dimensionless value |
| S-parameter imaginary part | Dimensionless value |
Smith Chart Format
Smith chart format is used for representation of impedance values for DUT reflection measurements. In this format, the trace has the same points as in polar format.
Figure 34 Smith chart format
The Smith chart does not have a frequency axis, so frequency is indicated by markers. There are five types of Smith chart formats corresponding to the data displayed by the marker; the traces remain the same for all the format types.
Table 12: Smith chart formats
| Format Type Description | Label | Data Displayed by Marker | Measurement Unit (Y-axis) |
|---|---|---|---|
| Linear Magnitude and Phase | Smith (Lin) | S-parameter linear magnitude | Dimensionless value |
| S-parameter phase | Degree () | ||
| Logarithmic Magnitude and Phase | Smith (Log) | S-parameter logarithmic magnitude | Decibel (dB) |
| S-parameter phase | Degree () | ||
| Real and Imaginary Parts | Smith (Re/Im) | S-parameter real part | Dimensionless value |
| S-parameter imaginary part | Dimensionless value | ||
| Complex Impedance (at Input) | Smith (R + jX) | Resistance at input: | Ohm (Ω) |
| Reactance at input: | Ohm (Ω) | ||
| Equivalent capacitance or inductance: | Farad (F) | ||
| Complex admittance (at Input) | Smith (G + jB) | Conductance at input: | Siemens (S) |
| Susceptance at input: | Siemens (S) | ||
| Equivalent capacitance or inductance: | Farad (F) |
Z0 – test port impedance. Z0 setting is described in section 5.2.12.
Data Format Setting
You can select the format for each trace of the channel individually. Before you set the format, first activate the trace.
To choose a rectangular, Smith, or Polar format, use the softkeys.