To apply this to the MMD, we created a unique Current-
Mode Discriminator (CMD). The CMD operates somewhat like a common-mode choke, but is engineered to maximize the separation of these two current modes well beyond conventional parameters.

In the MMD, the differential signal on the feedline passes freely through the CMD (with almost zero loss) at one end of the antenna and continues along the dipole leg (which is also coax) to the antenna's center feedpoint.. One 'half' of the antenna current continues on to the end of the antenna, the other 'half' flows from the center back along the coax in common mode until it meets the CMD, where the dipole leg is electrically terminated for any common-mode current.  

Thus the coax both delivers the current to the center in differential mode and carries the antenna current back along the coax to the CMD in common mode, without 
any interaction between them. And there it is - the Mixed-Mode Dipole.

The MMD is not the first antenna attempting to use this principle, but other designs have generally missed the boat, usually because the operating principles were 
poorly understood or applied.

A well-known example of this is the RFD, for which it is claimed that skin effect plays a role in keeping the different modes of current separate - our R+D program showed this to be untrue. The RFD is most often described with a wound-coax choke at one end, which actually performs very poorly.  Some designs even suggest the choke should be tuned to resonance - a terrible idea!

Our intensive R+D program identified many opportunities to revise and then optimize the operating parameters of this type of antenna, and the result found in the MMD is a truly superior performer.

The end-fed MMD eliminates the high-impedance, frequency-sensitive components found in most end-fed antennas while retaining the standard dipole advantages of low impedance center-feed and band-agile tuning.  

Better than either, the MMD design automatically interrupts any common-mode currents flowing on the feedline to the radio, reducing rf at the transmitter and reducing noise coupled to a receiver. And the feedline's location in a deep null at the antenna's end eliminates any antenna-pattern disturbances.

The MMD is constructed with high-quality RG-174 coax - tough, durable, and light weight - and should last for years. With all its advantages, it seems possible that the MMD design could become the new 'standard' dipole. It is competitive in cost, complexity and performance, while being far easier to install and operate in either fixed or portable settings.