This invention is directed to microwave devices for transferring power between one input and two outputs or vice versa.
Isolated coaxial four port devices can take two forms: split tee devices as described by Parad and Moynihan (IEEE MTT Transactions, Jan. 1965) and coupled line devices. The split tee device offers benefit in power division equality over the coupled line device. In general, the split tee device is inferior at power handling due to the fact that, one or more load resistors, are inefficient in their ability to dissipate the heat generated within themselves due to reflected power. Even the coupled line device has power and size shortcomings due to the fact the coaxial loads are large and inefficient.
The magic tee disclosed herein, unlike the aforementioned devices, has the capability of being able to handle more power than the coaxial transmission lines and connectors leading into and out of it.
This magic tee device of the invention has many applications. One use is an isolated power divider. Since the tee of this disclosure is a split tee device, it has exceptional amplitude tracking properties between ports. It is an isolated device so that it offers isolation between output ports. A common application is for a high power source to transmit its output to two antennas. Isolation between output ports insures undisturbed power flow to each of the antennas if the other is interrupted.
Another use of the magic tee device of this invention is a combiner. Here two equal in phase signals are combined to form a common output. If the signals are not in phase or unequal, the isolation property protects each transmitting sources from the other.
In both these applications the magic tee device of this invention works at a power level well in excess of present techniques.