For more than a decade, RF Cascade Workbook 2005™ has been the de facto standard for spreadsheet-based RF system cascade analysis. Wireless System Designer™ is the next phase in the evolution - not just an upgrade from RFCW2005. If you know how to use Excel and you know anything about cascaded system calculations, then you know how to use RF Cascade Workbook 2018™(aka Wireless System Designer™). This is significantly easier and faster than using the multi-thousand dollar simulators when a quick system analysis is all that is needed. Hundreds of hours have gone into developing this tool. Please see Wireless System Designer™ intro video below for an overview of features.
Mouse-over Comments for Cells
Excel's cell comment feature is use extensively to provide guidance for Wireless System Designer™ (WSD). The contents of all the hints - and more - can be found on the "Help" worksheet (click the tab at the bottom). The "Help" worksheet, cell mouse-over comments, and this web page comprise the totality of documentation for Wireless System Designer™. There is no separate document available. RF Cascade Workbook 2005™ should also be useful since it extensively documents formulas. Combined, there is a lot of information about not just how to use WSD, but also how cascaded system analysis works. RF Cafe is also chock full of related information, so one way or the other, you're covered.
Assistance: Because the price for Wireless System Designer™ is so low, I cannot provide any level of assistance with setup or operation. After all, you're getting an amazingly feature-filled program for less than an hour of an engineer's billable time. Reported errors, if any, will be addressed ASAP.
Macros: You must enable macros to run or you cannot use Wireless System Designer.
System Requirements: Excel 2007 & Windows 2008 or newer. These instructions and screenshots were made in Excel 2007, so your screen and menu placements might be a little different. I verified that everything works fine all the way through Excel 2016.
Help: Here is the complete Help Page from Wireless System Designer™.
Disclaimer:Wireless System Designer™ is offered AS IS. Your use of Wireless System Designer™ implies you alone accept responsibility for results obtained through its use, and will hold harmless Kirt Blattenberger, RF Cafe, and all legal assigns for any losses incurred through its use. Wireless System Designer™ has been tested very thoroughly, and there are no known problems at the time of this release. Discrepancies that affect accurate results, if discovered, will be fixed ASAP and a replacement version will be provided at no cost. Also, any and all User modifications to Wireless System Designer™ - other than entering values in the provided Unlocked cells, negates any and all responsibility by RF Cafe for the integrity of the software. Unprotecting a worksheet negates responsibility by RF Cafe.
Locked vs. Unlocked Cells and VBA Code
Protecting & Unprotecting the Worksheet
Use Excel's Protect Sheet and Unprotect Sheet commands to lock and unlock, respectively, the cells. Use the Password provided in the e-mail sent to you with the file attached. I will be glad to provide it to you again with a proof of purchase.
When Protecting the worksheet, be sure to select ALL the check boxes in order to ensure that the macros will run (click thumbnail above). You might need to scroll down in the window to access all the check boxes. See Worksheet Protection information on the WSD "Help" page.
Since the complete worksheet occupies nearly 900 rows, a convenient drop-down menu is provided to move up and down the page. Information necessary for the navigation to function is in the cell behind the menu, so if you accidently overwrite the cells, navigation no longer works (keep Protection turned on).
Hiding and Unhiding Columns
Rather than deleting and/or adding component stage columns, it is much simpler to Hide and/or Unhide columns. Doing so retains all the information without having to go through all the steps needed for deleting and/or adding columns. All the input and calculated is retained and included in the overall output, but the Hidden stage columns are not included in the charts. Hiding component stage columns can be a good way to exclude unneeded plots from the charts without requiring you to delete/add data series - which is itself a pain to do.
System Cascade Charts
Charts are pre-configured for plotting all calculated cascade parameters. Auto-scaling of the axes is the default, but you can change all aspects of the chart formats per Excel standard. Select chart to display using drop-down menu.
These four top-level overall system parameters are used for many calculations. Be sure to define them along with the individual stage component parameters.
Build System Block Diagram
Build your system block diagram using the provided images or make your own. Click on the "Icons" tab at the bottom of the page to access and copy the desired icon (58x32 pixels), then paste it into the block diagram. Use Excel's standard Objects alignment and spacing tools for a perfect layout.
Specify Component Parameters
Enter each stage's nominal and tolerance values. Error checking is provided for exceeding power or gain limits (see below), no negative noise figure (NF), making sure NF is equal to absolute value of a negative gain component, etc. Errors are reported in the "Status" cells. Two rows f user-defined cells are provided for formulas along with a "User Defined" chart that displays the cell data.
Set Limits on Gain and Power Input Values
Set maximum values for stage component input parameters. These values are used for Data Validation in the input parameter cells. This results in a limit where the charts auto-scale, since entering a null value of, say +999 dBm for IP3 will render its affect utterly unnoticeable by the system, the IP3 chart will auto-scale to +1000 dBm or more while the IP3 level in your actual system might be a maximum of +50 dBm. The useful data would then be crunched almost entirely at the bottom 5% of the chart. Of course you can always go in and manually scale the chart axis minimum and maximum values as desired if you do use +999 dBm as the null value. This just keeps things reasonable in case you prefer to let the charts auto-scale. Besides, +100 dBm is good enough in most instances.
Specify Lower and Upper Frequency Sweep Limits for Filter Calculations
Enter the lower and upper frequency range for calculating the system response inclusive of filters and frequency conversion stages. 175 equally spaced frequency steps are calculated for all stages. Depending on your system, you might want to do sweeps across the entire input band of concern, then do narrower sweeps that will provide finer detail within your smaller filter bandwidths.
Note: the Lower frequency cannot be zero (0) because of the logarithmic horizontal chart scale. The smallest value permitted is 10-12, which is small enough to include 1 Hz even when the Upper frequency is 1 THz.
Every stage can contain a frequency-dependent component which can be an actual filter or a model of the frequency response of an amplifier, cable, coupler, etc. WSD checks to make sure all required inputs are present and alerts you if they are not. For example, if you select a bandpass filter and do not enter a lower frequency or if you use a Chebyshev and do not enter a ripple value (or if you enter invalid values, like lower frequency greater than upper frequency).
Frequency Translation (Mixers | Modulators) Specifications
As with the filter specifications, every stage can have a frequency translation. That means there is no limit to the number of frequency conversions your system can have, although from a practical standpoint you will probably never have more than three. WSD checks to make sure all required inputs are present and alerts you if they are not.
Frequency-Dependent Power Levels
Frequency-dependent power levels based on filter responses and frequency translations are calculated separately from the other system cascade calculations (NF, IP2, IP3, etc.). Along with the filter response, all nominal stage component gains are included. Results are plotted in the "Frequency Response" ("Signal Power vs. Frequency") chart. These frequency-dependent gains and power levels are not used in any of other cascade calculations (NF, IP2, IP3, etc.). Note that frequency and power levels presented this matrix are actually calculated in cells below Row 540, but are done this way to conveniently place power levels next to their associated frequencies while making data selection for the chart simpler (take my word for it).
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