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Updated December 23, 2013

New for December 2013: we have an update to the S-parameter Utilities spreadsheet, thanks to Ishan.

Also new for December 2013, we have further analyses of resistive splitters thanks to Andy.

We at TEGAM were designing an amplifier test bench and had occasion to look on your site for some splitter design input.  I was intrigued with the approach taken by Adams at www.microwaves101.com/encyclopedia/Resistive_splitter1.cfm but really wanted to be able to control the attenuation to both output ports.  After a bit of fiddling, I came up with a two output port splitter design calculator that lets you set the attenuation to each port (within practical limits).  The derivation and calculator are attached in the files names, “Two Output Four DOF”.

In a further step, our design needed a splitter with two equal outputs and a third monitoring output with some “nice” ratio to the others.  That was a relatively simple step and is attached as “Three Output Four DOF”.

New for October 2013: this download is a MatLab program that calculates transmission line properties, including microstrip, coupled stripline and coplanar lines. It was contributed by Lakshmi from NITT. You can learn how it works on this page. Thanks again!

Download the MatLab T-line calculator (in the form of a zip file)

New for August 2013: Here's an airbridge inductance calculator in Excel, contributed by Matt. The math appears on this page. Note that Matt change to units to more-relevant picoHenries. Thanks!

New for May 2013: How many times have you had to convert electrical degrees to length or delay? Here's a simple spreadsheet that does the calculation three ways. If you are designing a time delay unit, you know what we are talking about... while you are thinking about this, commit the following to memory so you can do the calculation in your head: 300mm (~one foot) is one nanosecond delay in free space, and is one wavelength (360 degrees) at 1 GHz.

New for March 2013: Here is a poster on the topic of Women in Microwaves, that was prepared by Dr. S. Raghavan and Prof. S. Suganthi. Check out NITT's Microwaves101 page for more information on microwave education in India.

New for December 2012: Read all about the future by grabbing a copy of GLOBAL TRENDS 2030: ALTERNATIVE WORLDS, a publication of the National Intelligence Council. It's 23 MB so it might take a while...

New for August 2012: Skip down to obtain a free copy of Matthaei, Young and Jones filter book!

If you have something we can add to this area, we'll trade you a free gift, or if your work is really outstanding, we'll pay you for it (but not much!)

The spreadsheets below supplement our calculator page, and in general offer data-crunching that is too complicated to put onto an HTML page for you.

A lot of people ask us "why do you create spreadsheets for calculating stuff like group delay, when all these calculations and more are built into Agilent's ADS software?" There are two reasons, Silly Rabbit: first, not everyone has spent \$50K on software, but everyone has Excel. And second, you have a lot more options for presenting data using Excel. How many times have you sat through a design review where all of the plots were cut and pasted from ADS (or worse, Eagleware Genesys) outputs, and you can't identify what you're looking at or what any of the values are?

New for September 2012: we have two new downloads, one for calculating capacitance and one for calculating complex impedance from S-parameters. The capacitance calculator does the very simple job of calculating parallel plate capacitance, but it will save you the trouble of unit conversion and looking up the Dk of stuff like silicon nitride. While we were at it we included the capacitive reactance calculation at the frequency of your choice.

Chris provided the calculator for converting magnitude and phase to impedances, which is a fundamental problem that belongs on any final exam in a microwave class (tell your boos that and ask him to derive it some time for fun).

Update December 2012: the impedance calculator download has caused a lot of trouble, which may or may not be related to the age of this web site (hopefully we will globally fix this problem and more during 2013...) The problem is that in most browsers, it is not possible to download a .xlsx file (the 2007 version or later of an Excel file) from this Cold Fusion page that was created in Dreamweaver 11.5 (in case you want to assign blame). The file that Chris sent us was the first Excel file that we have dealt with that could not be converted back to .xls due to some tricks he employed. Many people have tried unsuccessfully to download it, and a small number have written to us to complain and we have sent them the file by email. Now we offer the ultimate patch: we zipped it. Download it and and unzip. Sorry for the inconvenience!

New for August 2010! Here's a spreadsheet that extract Dk and Df from transmission line measurements. The technique is explained on this page. The spreadsheet contains some data that was provided to us, you'll have to copy over it, and perhaps do some formatting...

New for May 2010! The Professor has donated his image rejection spreadsheet. Thanks! This file will help you understand the relationships between phase and amplitude imbalances, and overall image rejection, which is also explained on this page.

New for October 2009! Here's a spreadsheet that calculates characteristic impedance of a transmission line based on measure reflection coefficient. It's explained on this page.

New for September 2009! Here's a spreadsheet that performs via-hole inductance for microstrip circuits.

New for May 2009! In the spreadsheet below, Chris answers an important attenuator question. What if you are building a pi attenuator from standard resistors and you're stuck with 1% values? This spreadsheet calculates exact attenuation and return loss from the inexact resistors, for 0.2 dB step size. Thanks, Chris!

Also new for May 2009! We have a modification to our famous S-parameter Utilities spreadsheet, from Kelvin. The new spreadsheet adds stability measure on the plot of stability factor and maximum available gain. Click here to jump down to it.

New for March 2009! Here's a spreadsheet for looking at mixer spurs, contributed by Gerald. Thanks! You need to enable macros to get it to work. Also, it was originally intended for Europeans so decimals are separated by commas instead of points. Here's a companion page on how to use it.

New for February 2009! Here's a simple spur table calculator from Larry. If you go here you can read a reprint of a related Microwave Journal article that describes intermodulation tables in mixer simulations. Thanks! And we're sorry in advance if/when the link to the article breaks!

New for January 2009! Here's a spreadsheet that not only calculates the ideal values for lumped elements in a high-pass/low-pass phase shifter, it plots the frequency responses of the two filters and their relative phases over frequency! This is a good example of using ABCD parameters and complex math in a spreadsheet, we have started a description of the spreadsheet here. A word of caution (and we found this out the hard way but we still don't have a full explanation...) this is an Excel 2003 file, you may have trouble trying to run it in Windows Vista, because the analysis tool-pak that does complex math (sometimes) gets fubared! The spreadsheet may still be a little rough around the edges, please give us some feedback for future improvements.

Also new for January 2009! Here's a link budget calculator from Andre. He supplies this spreadsheet to engineers considering point-to-point wireless connections. OK, this is practically a free advertisement for Adtran, so when you contact them, tell them you found them through this web site and that maybe they should cough up for a sponsorship or we'll remove the link budget calculator one of these days!

New for December 2008! Here's a freespace path loss calculator contributed by Robert! It is something he put together for coworkers so they could understand Wi-Fi a little better. It allows you to customize the general RF situation in the environment (allowing you to match real world better to estimations). It also allows you to select different frequency ranges. This is an Excel 2007 file, software which we don't have, so we have yet to try it! If anyone has any comments of suggestions we will relay them to Robert. Note that the file is zipped, we had to do this because most web browsers won't know what to do with an "xlsx" file!

New for October 2008! Here a spreadsheet for analyzing even and odd mode impedances of coupled-line couplers.

New for August 2008! We now have a multi-section Wilkinson power divider tool for Excel. It is (hopefully) described in detail on this page. It will analyze up to eight sections but is limited to equal split. The transmission line sections are based on Chebyshev equal-ripple transformer calculations and are exact for the bandwidth that you specify. The resistor calculations are not perfected yet so you might not get the best possible isolation without optimizing the resistors on your own. Be sure to "enable macros" when you open it, and you might have to enable the "analysis tookpaks" to get it to work (look under "tools", "add-ins"...)

New for July 2008! Here's a "reverse microstrip calculator" spreadsheet that lets you specify impedance and it solves for line width. It use linear interpolation, and is explained on this page.

New for June 2008! here's a simple spreadsheet that will help you understand the concept of frequency translators

New for June 2008! Here's a spreadsheet from Nick, which we'll let him describe...

I enjoy Microwaves101 far too much to be considered normal. Accordingly, the enclosed utility might spark some interest on the subject of VNA calibration fundamentals in some other kindred spirit. I can't imagine another forum that would possibly have any interest at all...

Yes, Nick, Microwaves101 will always provide a home here for YAODs. Please follow up with some text explaining the spreadsheet and we'll post a page with an example...

Updated August 2009! Here's a spreadsheet from Chip that simulates the Klopfenstein taper. We made it more usable, with 21 impedance steps. We're working on an explanation on this page.

And updated further for June 2013! Thanks to David, the spreadsheet below now has a correction to the math which was published by Kajfez and Prewitt in 1973. David also made other improvements to make the spreadsheet more usable. Thanks again!

Also new for May 2008! Here's our version of a poor man's CAD tool for doing layouts (like Visio, or a really cheap version of AutoCAD). It's all explained on this page.

New for April 2008! This Excel spreadsheet calculates free space loss and and Fresnel zone radii. Inputs are frequency in GHz, transmitter TPO, antenna gain, transmission line loss, path distance, RX threshold, and obstruction distance for the Fresnel radius. Outputs are freespace loss in dBm, RX signal in dBm, RX fade margin, 1st, 2nd, 3rd and 4th Fresnel zone radii at the obstruction (calc) point.

Contributed by Tim!

New for March 2008! We've finally got around to dressing up our VSWR spreadsheet into something we're proud of! We fixed the math, and added a slider bar so you can animate the waveforms. Note: you have to enable macros in order to get this spreadsheet to work! This spreadsheet has its own page of instructions located here.

New for February 2008! Here's a spreadsheet that shows you how to do linear interpolation in Excel, a valuable skill in any engineering field. We're working on a page that describes this calculation.

Added March 2008. Here's a spreadsheet contributed by Harald that shows you how to access the polynomial curve fitting capabilities of Excel! Here's Harald's description of its capabilities:

Everybody knows that you can produce a graph and add a polyline to it. But do you know, that you also can calculate the coefficients for a polynomial in Excel from a set of data and use them in your spreadsheet directly? You also can display the function of this polyline in the graph. You can copy and paste this formula into a cell for further use in the spreadsheet. It works, but you have only the accuracy as displayed in the graph and it is a lot of work. I did that until a coworker came up and said there is a simpler way to do it without creating a graph and the copy and paste work.

This function is very well hidden in Excel and not easy to find. I created an example spreadsheet to show how it works. Up to which order of polynomial it works, I have not tried out yet. The benefit of this function is, that you have the full accuracy of Excel for each coefficient, this is especially important for higher orders of polynomials.

The Excel Version I have is Excel 2003, the conditional sum wizard needs to be installed.

Also new for February 2008! Here's an RF unit converter from Frank. Thanks! It's an executable file that converts watts to dB-stuff and voltages, and more. Below is a screen capture that illustrates the capabilities:

And also new for February 2008! We have a new page that offers some free downloads courtesy of the U.S. Navy! The Navy Electricity and Electronics Training Series (NEETS) was written as part of the non-resident training course series and released to the public in 1998. We've only posted the topics that have to do with microwaves, radar and radio, but if there's enough interest we might upload the entire set. You can find these training manuals on many other web sites, but few have the bandwidth that we have for rapid downloads. Some lesser web sites even try to sell them! Thanks to Steve for suggesting this idea!

Improved for August 2009! The previous version was missing a couple of curves. We've created a bare-bones Smith Chart using equations for circles inside an Excel file. Then we stripped away the equations and left just the data. You can use this file any way you like, to plot data on the Smith Chart inside Excel. We'll be using it on some future spreadsheets, you betcha.

New for December 2007! Here's Kire's level diagram spreadsheet. Kire is one of our best "answerers" on the Microwaves101 message board, he's a prime example of what makes this a great web site.

New for December 2007! Phil sent us a microstrip miter spreadsheet, thank you sir! In his own words...

Here’s a calculator that I made for quickly making miters in AutoCAD. Your's, like all other ones I’ve seen reference the same A, X, and D dimensions. However, to draw a miter in AutoCAD with these dimensions can get tedious with the keystroke entry of perpendiculars, offsets, and trim commands, etc. and then have to repeat it on an assembly with many bends.

With this calculator, you enter the bend angle and it will calculate the distance for you to enter when you invoke the CHAMFER command in AutoCAD. This will quickly let you put the optimum miter on any arbitrary angle from 0 to 90 degrees and you can just click-click-click your way through any bend.

The table below the calculator just takes the equation and fills in a variety of widths and angles.

Pardon the minimal graphics, I made this not as a full self-explanatory file, but just something simple to give our CAD guys to speed up their work. Feel free to use or modify any of it, but this only works for AutoCAD. Other tools use a different method for calculating miters.

New for October 2007! Here's a spreadsheet that analyzes coupled-line couplers. You can vary the coupling factor, then see what an ideal coupler does over frequency. Be sure to turn on Excel's Analysis Toolpak!

New for August 2007: here's a spreadsheet that calculates resistor values for minimum loss L-pads which are described here:

New for May 2007: here's the start of a spreadsheet that looks at the array factor for phased array antenna calculations. Well, OK, it only looks at a single line of antennas (from 1 to 101), it would be too big to download if it simulated an entire array in two dimensions. It is far from finished, but maybe some smart person out there can take over for us and put some more effort into it. It is useful for looking at the various tradeoffs of gain versus number of elements, grating lobes as a function of element spacing, number of phase shifter bits, type of phase shifter, and a few other things. Feedback is appreciated!

New for December 2007: we combined the waveguide table contributed by Alan from NZ with our waveguide loss spreadsheet, and we added the capability to model dielectrically-loaded waveguides (which coincidentally has a new page here at Microwaves101!) There's a mess of improvements, including a pull-down table for selecting different conductors, and some new graphs.

New for December 2006: here's a rectangular waveguide table that is more complete than the one we have on this page. It was contributed by Alan D. from NZ. It has the three primary official designations along with some commercial designations, and interior dimensions are given in millimeters and inches.

Here's the start of an optimum miter calculator...

Updated January 2011: we fixed a bug in our coax calculator spreadsheet, the loss tangent of foamed PTFE was way too high, as pointed out by Joe who was getting ridiculous loss numbers when simulating RG6! There is perhaps no more easily analyzed transmission line than coax. Our spreadsheet performs the exact calculation of metal losses of coax with frequency (splitting out the calculations for center and outer conductors). It also computes dielectric losses due to loss tangent and dielectric conductivity and a ton of other parameters like characteristic impedance, capacitance and inductance per unit length, cutoff frequency, etc. The spreadsheet handles the offset coax calculation. See why our spreadsheet is a ton more useful than Agilent's ADS for analyzing coax! Thanks to Sergio from Italy, the latest version adds surface roughness to the calculation, a topic that we all need to better understand...

Updated May 2010! Here's a multidielectric coax calculator, contributed by Alex R. We recently corrected a problem with the cut-off frequency calculation for single dielectric, which was pointed out by Andrew (thanks!) It will calculate characteristic impedance of coax that contains up to five concentric dielectrics! Be sure to check out our page that explains the math.

Updated for September 2007: here's a filter calculator from Vlad, which does lumped element calculations (Chebyshev and Butterworth) and is very cool and admittedly better than the Excel calculator that we offer farther down the page. We now have a page that describes how to operate Vlad's calculator (but it's so simple you could figure most of it out yourself). We've had a lot of positive feedback about this calculator. The latest version offers the uses control over the plot axes. Please send us your comments on this calculator, Vlad volunteers to fix any problems you have!

New for July 2006: here's a MATLAB (c) tool for cylindrical resonant cavities. Contributed by Itzik!

Download the cylindrical resonant cavity calculator (in the form of a zip file)

Updated December 19, 2013: our S-parameter Utilities spreadsheet is the ultimate tool for manipulating S-parameters into all manner of plots, including group delay, K-factor, maximum available gain, VSWR, mismatch loss, loss factor, and input and output impedance plots. You can now quickly plot all of these parameters, from any manufacturers' S-parameters that you can download! We recently added the ability to calculate length of a transmission line (if Keffective is known), or velocity factor and Keffective if length is known. The spreadsheet has the ability to import data in real/imaginary format (in addition to magnitude or dB). It provides reference plane extension capability, and averaging to the group delay, VF, Keffective and length calculation, and even does Smith chart plots! We recently fixed a bug in the GMAX calculation which fixes a problem where 15 digits of precision within Excel sometimes aren't enough! (Explanation of this statement can be found here.) The spreadsheet can handle 2001 lines of data, if you want a smaller file it's up to you to truncate it. The latest version contains Mu1 and Mu2 calculations, tow more ways to look at stability. Mu1 and Mu2 should always be greater than 1.

Revised for February 14, 2013! Back in 2006 we created the heart-shaped S-parameters file and offered it in a spreadsheet download. We all know how SNP files sometimes don't work, so we updated the file slightly and it has been verified to work in Microwave Office. We added a second smaller heart while we were at it. Just tell your Valentine to plot all four S-parameters on a Smith Chart, and he/she will get the image below (plotted in MWO). We had to zip the file, otherwise it won't go through the download chute (it doesn't like the .S2P extension).

If you prefer, here's our S-parameter utility spreadsheet with the "heart curve" built in so you don't have to load the S-parameters into Excel. If you're lazy, just grab the graphic below and toss it into a steamy email! Here are the equations that we used to generate this graphic, we adapted them from something we found on the worldwide web.

Here's a download for looking at mixer waveforms. We have a new mixer waveform page that will show you how to use this to understand how a mixer works, in the time domain.

Originally Chris and Graham from across the pond have sent us a cool spreadsheet for calculating mixer spurious products! It's as good as the one at Hittite.com, but because you download it before you use it, no one will ever know your secret frequencies! The Microwaves101 Professor has outdone them with an expanded mixer spur calculator which you can now download. We have also put up a page on the instructions for using the revised calculator, check it out!

Here's one engineer's collection of aerospace slang, it's from Carl F. Gauze who works at Anonymous Aerospace. (Danger Will Robinson, this document contains the F-word, so don't download it if you have a problem with that!) Click here to go to the Microwaves101 slang dictionary.

Much improved for February 2005: here is our lumped-element Chebyshev filter calculator! It now includes plotting capability, so you can synthesize filters and play with them in real time! (We are still working some bugs, be sure to look over the "readme" page.) Using this Excel spreadsheet you can calculate ideal elements for N=3, N=4 and N=5 order low-pass, high-pass, and band-pass filters, and you get to specify the passband and the ripple. A full description is given on our section on lumped-element filters.

New for January 2005: this SPICE skin effect cable attenuation model was contributed by Mike Leung of Northrop Grumman Space Technologies (formally TRW). This is for engineers who model circuits using SPICE, which unfortunately excludes everybody at Microwaves101! But it looks cool so we will pass it along!

Here's a spreadsheet for calculating N-section impedance transformers, to match two real impedances that you specify! Improved for November 2005! The "bug" is fixed, you can now transform in both directions (Z1<Z2, Z1>Z2). In July, the Professor redid the calculator (again!), it now calculates equal-ripple, maximally flat and exponential transformers (up to eight sections). It even displays the frequency response, you don't need ADS or Eagleware or other expensive software! Note: If your Excel software doesn't have the "Analysis ToolPak" installed , you might not be able to view the graphs properly. Go to "tools", then "Add-Ins", then check the box for "analysis ToolPak". Check out our page on quarterwave tricks for more information on transformers.

Our RF sheet resistance spreadsheet calculates the equivalent ohms per square versus frequency for up to three layers of different metals, using the skin depth equation and a little calculus that we already solved so you won't have to tax your tired brain! This is a feature you won't find on Agilent's ADS software, and if you did it would have more bugs than Mount Katahdin! It also has a single-metalization option that plots resistivity and conductivity for 1, 2, 3, 4 or 5 skin depths (per request of Chris G.) The spreadsheet is totally unlocked, and features a pull-down menu of metal parameters for your convenience. Try out our on-line skin-depth calculator for quick analyses!

New for October 2006: here's a couple of Visio files that contain graphics for coax and waveguide schematics of block diagrams. These were supplied by Ted! Thanks!

What would a microwave web site be without some handy Smith chart downloads? Here are some great Smith charts that are low in megabytes but high in resolution, perfect for documents!

Here's a Microsoft Word document that contains schematic symbols such as resistors, capacitors, circulators, attenuators and switches, power dividers, bias tees, DC blocks and assorted other microwave components. In the latest edition (July 2011), we've added a symbol for a ferrite bead, per William's request. You can use this file to create your own schematics for documents and presentations. Please send your feedback on this work-in-progress to techwriter@microwaves101.com.

### Cool Microwaves101 posters!

New for August 2005: check out Varian's "History of Radar" ads, those cats were real gone!

Here's a poster for your lab in PDF format. Print it and post it and help us Fite Microwave Stupidity!

Are you sick and tired of picking up a connector out in your lab and finding that some one else wrecked it? The Unknown Editor has a solution for you. Post this handy guide to Connector Care in your lab! It's updated for 2007, thanks to Vinny who caught a mistake on the torque spec (inch ounces should have read inch pounds!)

At Microwaves101 we pride ourselves on building microwave information into our encyclopedia, so it is indexed, cross-linked, and totally convenient. Not like some crummy pdf data sheets and app notes that suppliers put up for you to go crazy waiting two minutes to download so you can spend ten minutes looking for and probably not finding the info you need. We also make it a point not to steal stuff from other web sites and offer it as our own.

But in some cases, we realize there are documents out in the public domain that we can collect and offer in one convenient place. Here's two examples.

New for August 2012! Thanks to Rob, we now offer Microwaves101 Hall-of-Famers Matthaei, Young and Jones "Microwave Filters, Impedance Matching Networks and Coupling Structures" which dates back to 1963 but is still the most complete book on microwave filters ever written, at 1,000 pages. This material was developed under government contract and hence is approved for public release by DTIC (which is where we found it).

New for December 2010! Thanks to Chris, we now offer a copy of an 1954 NRL report dating from 1954, on the design and calibration of horn antennas. NRL Report 4433 DESIGN AND CALIBRATION OF MICROWAVE ANTENNA GAIN STANDARDS, by William T. Slayton, gives dimensions for construction of a series of microwave horns of known gain, and may be used as a calibration reference. The horns are designed to match up well to standard waveguide sizes. Virtually all standard gain horns on the market follow the dimensions called out in this report.

We found the document at the Defense Technical Information Center, specifically here. So we'll assume it is public domain, and offer it through the link below. Enjoy!

Download DESIGN AND CALIBRATION OF MICROWAVE ANTENNA GAIN STANDARDS, NRL Report 4433

New for April 2011! We have much more on material on William Slayton thanks to his daughter Charlotte! Here is a much better copy of the NRL report.

Download DESIGN AND CALIBRATION OF MICROWAVE ANTENNA GAIN STANDARDS, NRL Report 4433 (Improved copy)

Here is an article he wrote for Electronics Magazine in 1955, on the same topic!

Finally, here is a speech he gave in 1980 about his experience at NRL, three years after his 1977 retirement.

It's no wonder that William Slayton is in the Microwave Hall of Fame!

New for February 2010! The Quadrennial Defense Review report is put together every four years by the Department of Defense, the latest was issued February 2010. This report defines where we are on the war on terror, as well as the to-be state. If you want to win a government defense contract you should read this and reference it in your proposal.

Here's the previous QDR report in case you want to see what changed.

The US Department of Homeland Security also issued a quadrennial review report in February 2010.

DARPA has a strategic plan, you should read it!

The Navy's Office of Naval Research has a plan for science and technology, some of which is gonna involve some very high power microwaves...

The Navy released some great tutorial documents in 1998, including an entire series on electronics. We've posted the NEETS documents on a separate page.

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