Abstract: A system for extending the frequency range of an RF amplifier by improving the VSWR, and power handling capability of the amplifier, comprising a broadband reversing transformer, a first and a second amplifier coupled by means of a first and a second through-line quadrature coupler with the first quadrature coupler being connected to the inputs of the two amplifiers and the second quadrature coupler being connected to the outputs of the two amplifiers. The broadband reversing transformer is inserted in series with one of the two amplifiers enabling a signal at frequencies out of the passband of the quadrature couplers to pass through the through-lines port of the quadrature couplers, and thereby greatly extending the frequency range over which quadrature couplers may be used while, at the same time, retaining the usual combining and VSWR advantages of the couplers within their passbands.

Abstract: A system for providing a quadrature hybrid with a wide bandwidth and an extremely low amplitude imbalance. This system incorporates conventional quadrature hybrids as components and provide a system quadrature hybrid having a larger bandwidth and a far lower amplitude imbalance than that of any of the component quadrature hybrids. Typically, the system bandwidth improvement over that of the component hybrids is 60 percent, while the improvement in the imbalance is 6 to 1. These improvements are achieved using a system network consisting fundamentally of three conventional hybrids, a reversing divider and an in-phase divider, all of which are readily available components. This system provides a significant improvement over more complicated quadrature hybrid designs where filter networks are required to obtain wide bandwidth. The widest bandwidth components now abailable, including those using filter networks, can be incorporated in the present invention to provide an even wider system bandwidth.