RFsyscalc (Excel) spreadsheets

This spreadsheet was done to facilitate RF cascade analysis of communications systems. There were a few reasons I migrated from using a "commercial" product to using this spreadsheet:

If you want something more, I suggest looking at the tools offered at www.rfcafe.com as well as their links to other vendors' sites. Other options range from free to very modest registration fees up to several hundred dollars in a few cases.

Some plots

Provided to show the features of version 4.xxxx

Here's a graph of how an example Receiver's SNR varies with input signal range .  The flat spot in the curve shows the effect of "delayed" AGC.  This type of AGC is typically setup so that it is inactive until the signal level is high enough  that the additional attenuation introduced will not degrade the SNR to below a perfectly usable value.  This technique allows both good small signal performance and enhanced strong signal handling capability (especially off-channel) when implemented properly.  The graph shown is from an example provided  (that exaggerated the effect to show what the delayed AGC is all about).  Note that with the spreadsheet you can implement the "delayed AGC" as a fixed step attenuator if you want ... just make the range that the device is active over extremely narrow -- this way it will go from one extreme of it's gain to another when the limit is reached!

This graph is of the level of two interfering tones (vs. offset from the channel center) required to cause a 3rd order IM product to fall in-band at the level of the thermal noise... effectively dropping the RX sensitivity by about 3 dB....

The features of this tool

Version information

Download...

Most recent version of "RFsyscalc" spreadsheet

(version 4.0h  uploaded 8/16/2004)

Note: all releases of RFsyscalc include copies of the old releases as well since the files are not very large.