While these types of couplers are quite handy, not many people too much about them, unless you are in the field of electronics or engineering, there would be very little cause to know these things offhand. However, here are some facts and a little behind the scenes information regarding a quadrature hybrid coupler.
With this type of coupler, the input is divided into two different signals. While the signals are indeed split, they still share a goal of trying to maintain magnitudes which are equal. These signals are always predetermined to be 90 degrees in their aperture of phase. Some of the types of couplers include couplers which are branch line and both Lange and overlay couplers.
One of the best known uses for these types of quadrature hybrid coupler is to use them to pair devices by matching them by impedence. They are used to create reflections of the devices which are then load terminated and then subsequently separated from the input of the quadrature hybrid coupler. It is for this reason that the 90 degree phase is used because only by using this method is this trick achieved.
If transistors are used in conjunction with the couplers, then it is referred to as a balanced amplifier. This second method is also used to create what are known as reflective attenuators. These particular devices are highly absorptive. They are also frequently used to amplify other power couplers. These are yet again referred to as balanced amplifiers.
As you can see, there are quite a few creative uses for these types of couplers. Only by knowing all about them and the technology and theories behind them can they be fully utilized to their maximum potential. These are great gadgets which have a lot to offer the interested user.