High frequency electrical network with frequency dependent characteristics having a constant input resistance

Claim 1

A constant resistance electrical network comprising in combination: a cavity resonator; a pair of separate couplers disposed within said cavity resonator in electrically insulated relation thereto, and each coupler having the same characteristic resistance; a first input coaxial line and a first output coaxial line leading to said cavity resonator and each having a center conductor connected to opposite ends of one coupler to form a first coupling loop within said cavity resonator; a second input coaxial line and a second output coaxial line leading to said cavity resonator and each having a center conductor connected to the opposite end of the other coupler to form a second coupling loop within said cavity resonator; each coupling loop being disposed in a plane transverse to the natural direction of propogation of resonant waves excited within the cavity resonator by said couplers and means terminating each of said output coaxial lines in said characteristic resistance, whereby when energy is applied to either input coaxial line none is reflected thereby and the energy is directed substantially only to the corresponding output coaxial line except when the energy is substantially at the resonant frequency of said cavity resonator whereupon the energy is directed substantially only to the other output coaxial line.