The Data File page of the Component Properties dialog box provides the means to attach an XML data file or a two-port S-parameter file to the currently selected component. When data is attached to a component, SysCalc creates and uses spline curves to represent the data points over frequency (and temperature if present). These curves represent the data exactly at the points contained within the data file and will provide a smooth estimation for analysis at points not explicitly contained in the data file. Assuming that the data file contains reasonable resolution over the frequency range, the smoothing will similarly provide reasonable estimation. SysCalc does not extrapolate for analysis points outside the ranges specified in the data file in either frequency or temperature; therefore, it is important for the file to provide data over the entire range of analysis. This includes image frequencies due to the presence of mixers.
S-parameter files are readily available from many vendors and are a convenient means for modeling the gain characteristics of components. SysCalc assumes that the component is matched at input and output according to the file's system impedance (See S-Parameters Files); therefore, only S21 is utilized during SysCalc's computations. While an S-Parameter file may technically contain noise figure data, SysCalc ignores the information.
The XML data file format used by SysCalc provides a comprehensive and flexible way to model any component parameter over frequency and/or temperature. The data could represent vendor published device data, or perhaps the multi-port performance of another circuit. You must first place the data in an ASCII file, which can then be referenced by as many components as desired. The XML data can be created and/or modified using Notepad (supplied with Windows) or with some other text editor. The format is shown below.
<Data_Root Schema='1'>
<!-- Freq Only specification -->
<Block Id='1' ParamOrder='Freq, Gain, NF, OP1dB' Format='Freq' Desc='Freq Only Data'>
<DataGroup>
<Data>900, 17.7, 3.75, 9.5</Data>
<Data>1000, 18.5, 3.85, 10</Data>
<Data>1100, 19.5, 3.95, 10.5</Data>
</DataGroup>
</Block>
<!-- Freq/Temperature specification -->
<Block Id='2' ParamOrder='Freq, Gain, NF, OP1dB' Format='Freq_Temp' Desc='Freq vs Temperature Data'>
<DataGroup Temperature='-55'>
<Data>900, 12.1, 1.75, 9.5</Data>
<Data>1000, 13.1, 1.85, 10</Data>
<Data>1100, 14.1, 1.95, 10.3</Data>
</DataGroup>
<DataGroup Temperature='0'>
<Data>900, 15.1, 2.75, 8.5</Data>
<Data>1000, 16.1, 2.85, 9</Data>
<Data>1100, 17.1, 2.95, 9.5</Data>
</DataGroup>
<DataGroup Temperature='16.85'>
<Data>900, 17.7, 3.75, 9.5</Data>
<Data>1000, 18.5, 3.85, 10</Data>
<Data>1100, 19.5, 3.95, 10.5</Data>
</DataGroup>
<DataGroup Temperature='85'>
<Data>900, 20.1, 4.75, 7.5</Data>
<Data>1000, 21.1, 4.85, 8</Data>
<Data>1100, 22.1, 4.95, 8.5</Data>
</DataGroup>
</Block>
<!-- Temperature Only specification -->
<Block Id='3' ParamOrder='Gain, NF, OP1dB' Format='Temp' Desc='Temperature Only Data'>
<DataGroup Temperature='-55'>
<Data>12.1, 1.75, 9.5</Data>
</DataGroup>
<DataGroup Temperature='0'>
<Data>15.1, 2.75, 8.5</Data>
</DataGroup>
<DataGroup Temperature='16.85'>
<Data>17.7, 3.75, 9.5</Data>
</DataGroup>
<DataGroup Temperature='85'>
<Data>20.1, 4.75, 7.5</Data>
</DataGroup>
</Block>
</Data_Root>
The XML data shown above has been indented to show the hierarchal nature of the information. Various elements or keywords are shown in black. Each element is case sensitive and therefore must be typed as shown. Some of the elements have attributes which are colored in blue. Comments are enclosed in <!-- --> and are colored purple. Free form data is shown in red.
Each data file can contain an unlimited number of data blocks each representing a unique collection of data. When attaching a file to a component, the user will have the opportunity to select the block of data to be used. The above file has three data blocks as delimited by the <Block></Block> elements. Each block must contain several attributes -
| Id - | A unique integer representing the data block. | |
| ParamOrder - | The parameter name(s) and order of the data that occurs between the <Data></Data> elements. The parameter names are the same as those that occur in the Properties Dialog and are case sensitive. | |
| Format - | The data organization of the block. Allowable values are Freq, Freq_Temp or Temp | |
| Desc- | A description of the data. The value may be empty but the Desc element must appear in the block. |
The 'Frequency only' data block is the simplest in structure and is shown above in the first block (Id='1'). The block can have only one DataGroup element. The data within the Data elements must occur in the same order as specified in the Block attribute, ParamOrder. The frequencies contained within the Data elements must not be duplicated and must occur in increasing order.
The 'Frequency/Temperature' data block is shown above in the block with Id='2'. The block must have two or more DataGroup elements with each DataGroup representing information at a specific temperature. The temperature, in °C, for each group is specified using the Temperature attribute. Temperature must occur in increasing order for the DataGroups. The frequencies contained within the Data elements must not be duplicated and must occur in increasing order within a DataGroup; moreover, each subsequent DataGroup must contain the same number of entries as the first DataGroup and contain the exact frequencies as the first as well.
The 'Temperature only' data block is shown above in the block with Id='3'. The block must have two or more DataGroup elements with each DataGroup representing information at a specific temperature. The data within the Data elements must occur in the same order as specified in the Block attribute, ParamOrder. The data for this block type must contain no frequency information.
To attach a data file to a component, double-click the component to invoke the Component Properties dialog. Select the Data File tab and click the Attach Data File button.
In the Open dialog select the desired data file. Information related to the selected data file is shown in the dialog. Since XML files may contain multiple data blocks, you may browse the blocks using the Prev/Next buttons. Click the Open button to attach the file to the current component.
Details of the attached file are shown on the Data File tab. To detach a file from the component, click the Detach Data File button.
