Welcome to EM Design’s New Website.  

We’ve designed this new site to serve two purposes: 1) to be easy to navigate, and 2) for technical personnel to learn about the performance capabilities of our products. Please take a few moments to look around – peruse our various products, read a bit about the projects we’re currently working on, and learn how the organization got its start.

If you have questions about our products or a new technical challenge you would like help addressing, we look forward to hearing from you.




The EM Design Distributed, Phase-Shift 3-Port Circulator.  “It’s Not Your Grandfather’s Junction 3-Port!”

In 2002, EM Design addressed the performance limitations of traditional 3-port junction circulators by developing (and patenting) a distributed, phase-shift 3-port circulator.

While many in the industry think ‘junction 3-port’ when they hear ‘distributed 3-port’ as an option for their project, it’s important to understand the differences between the two and the benefits of using a distributed 3-port in your system.

The distributed 3-port has some significant advantages:

  1. It is stable and has consistent operating performance.
  2. It has the ability to operate at higher peak and average powers.  For example, at S-band, the distributed 3-port circulator operates up to 8 MW peak power and 30 KW average power.
  3. It is not water temperature sensitive.
  4. It can also act as a replacement for larger 4-ports.  If your performance requirements can be met with this design, it eliminates a fourth port and the corresponding absorption load.  It is also significantly smaller.

For more information about this design, please see our Models 102483C, 102647, 102647A, 102647NP-S, 102788S and 102885.