Category Archives: Microwave Applications

MDL Excited for Largest Microwave Exhibit

For this year’s Microwave Week (June 1-6), the MDL team will be in Tampa Bay, Florida for the IEEE MTT International Microwave Symposium (IMS). The IMS is one of the largest exhibitions in the microwave industry hosting over 500 companies.  Attending this weeklong event is a great opportunity to participate in technical sessions, interactive forums, workshops, industrial exhibits, application seminars, and more!

If you plan on attending, visit MDL at booth 1715 to learn more about microwave components, sub-systems and assemblies including custom waveguide rotary joints and rotary switches, power combiners and dividers, and monopulse comparators just to name a few. Need help locating the MDL booth? Use IEEE’s interactive exhibitor list!


Won’t be able to attend IMS? Visit MDL’s website to learn more about our components, sub-systems and assemblies. Stay connected with MDL on Twitter, LinkedIN, YouTube and here on our blog for more news and events.

Stop Looking for Your Old HP Slide-Tool…

The days of searching through desk drawers for your old HP Slide-chart tool are finally a thing of the past with the launch of MDL’s newest tool online – the Reflectometer Calculator (as shown below).  This has always been a vital tool for correlating/converting VSWR to Return Loss or Reflection Coefficient. The Reflectometer Calculator also shows the contribution to overall Loss due to the Reflections (Mismatch Loss)!

Reflectometer Tool

The Reflectometer Calculator allows engineers to input any one of three known values, (Reflection Coefficient (p), VSWR or Return Loss), to quickly convert to the other unknown values. This tool allows the user to put their System or Component’s performance in perspective. Users can quickly convert to numbers they are comfortable using to determine the System or Component’s RF efficiency. The calculator will even provide engineers with a window of uncertainty for measurements taken with less than perfect systems (Coupler Directivity).

The tool will help you to answer these questions:

  1. What is the dB value for a 1.2:1 VSWR? Answer: (20.8dB)
  2. What portion of my Loss measurement is due to my device measuring a 1.5:1 VSWR? Answer: (0.175dB)
  3. What is the reflective coefficient of a product measuring a 1.3:1 VSWR? Answer: (0.13)

Looking for other tools to help you get the job done? Check out another popular tool from MDL – the Rigid Waveguide Slide Rule. It is available for download on your Android, Blackberry or OS devices. Download here.

Finding Just The Right Waveguide

Waveguide is still very much the transmission line of choice in a wide variety of applications, from commercial communications to military systems on land, at sea, and in the air. Waveguide transmission lines and components are also used in most deep-space applications, including on lunar programs and on the Space Shuttle.

Screen Shot 2013-09-10 at 7.50.54 AMFinding the right type of waveguide for an application, from 1 to 50 GHz, whether based on electrical or mechanical requirements, has never been easier, thanks to a unique rigid waveguide slide rule available on the website for Microwave Development Laboratories (MDL, The slide rule can be found on a webpage entitled simply “Rigid waveguide data.”

The left-hand side of the screen provides 23 boxes containing different rigid waveguide sizes by their Electronic Industries’ Association (EIA) designations, starting from WR229 through WR10. The right-hand side of the screen shows the slide rule for all the key specifications of a selected rigid waveguide size.

But these are just the beginning of the massive amount of data that is made available for each choice of different rigid waveguide size. The slide rule offers a recommended EIA frequency range in GHz for the selected rigid waveguide size, in terms of minimum and maximum operating frequencies, but also frequency (in GHz) and wavelength (in cm) for the waveguide’s TE10 cutoff mode. In the case of the WR90 example, a recommended operating frequency range of 8.20 to 12.40 GHz is listed, with a cutoff frequency of 6.557 GHz and cutoff wavelength of 4.572 cm.

The slide rule also shows the power ratings for a selected waveguide side, with minimum power rating of 0.33 MW and maximum rating of 0.47 MW for the WR90 example. In addition, the slide rule lists some fascinating details on a selected waveguide size, based on the type of materials with which the rigid waveguide section is constructed. For example, the slide rule shows theoretical minimum and maximum attenuation for waveguide at a selected size, as a function of different materials for the waveguide, such as copper, brass, and aluminum. Attenuation levels are shown in values of dB per 100 ft. of waveguide across the operating frequency range.

On the mechanical side, the handy slide rule shows inside and output dimensions for the waveguide size selected, in terms of width, height, and even dimensional tolerances. For the WR90 waveguide, for example, it shows inside width and height of 0.900 and 0.400 in., with outside width and height of 1.000 and 0.500 in., and dimensional tolerance of ±0.004 in. The slide rule even provides a dimension for a selected waveguide’s wall thickness, a value of 0.00 in. for the WR90 example.

Specifying a waveguide product

To simplify specifying a waveguide product, the slide rule shows different flange types in terms of material selection, such as brass or aluminum, and also shows the pertinent MDL model number for the different flange choice. The slide rule changes values instantly when another waveguide size is selected, allowing users to quickly browse through different waveguide sizes and designations to find the transmission line that is suitable for their application.

In addition to the personal computer (PC) version of the rigid waveguide slide rule, the application is also available for free download from the MDL website for use on mobile devices. Admittedly, peering at the waveguide sizes and specifications on the smaller screen of a mobile device is not the same satisfying experience as browsing through MDL’s waveguide choices on the screen of a PC. But having access to the application on a mobile device may prove to be handy for in-the-field specification of high-performance rigid waveguide transmission lines.

eTools for Diverse Applications

Screen Shot 2013-09-10 at 7.56.59 AMThe rigid waveguide slide rule is just one of the handy tools available on the “tool page” of MDL’s website, at The tool page also provides easy access to a large number of computer-aided-design (CAD) drawings (by means of password access) as well as an electronic version of the firm’s 133-page catalog, with electronic pages that can be flipped with the click of a mouse button. This catalog application shows all the details of a full-sized, printed catalog, but on the convenience of a computer screen, with the capability to print out selected pages or ranges of pages as needed. The electronic catalog itself includes tools which simplify enlarging or reducing the size of displayed pages and tools which show currently viewed pages in context with previous pages and pages to come, for quick scanning when in search of a particular solution. Considering the diversity of applications for rigid waveguide, these tools can help a wide range of users find the right waveguide for their jobs and help to find them quickly.