Abstract: A plurality of signals to be separated in time as well as in frequency are imultaneously applied to the input of a power amplifier whose output is applied to the input of a fast-tuned filter. The filter is capable of being almost-instantaneously tuned to any of the frequencies of the input signals to control the output at any given time or combinations of times. The filter is in the form of a coaxial section with an input to the inner conductor of the coaxial section and the output taken from a strip line, parallel to the inner coaxial conductor, coupled to a coaxial output cable at the top of the coaxial filter. The tuning is by a plurality of inductive spokes positioned at various locations within the filter, and connected between the inner and outer coaxial conductors by switching diodes, that are externally controlled, to provide almost instantaneous control of the resonant frequency of the filter.

Abstract: A multiple-frequency, coaxial filter and coupler has a cylindrical outer ing surrounding two or more axial sections of the cylinder separated by radial vanes. Each of these sections forms a separate coaxial filter with a separate input at one end and an output, which is formed by a separate strip line positioned near the center of the cylinder. All of the strip lines are joined to the center conductor of a common coaxial output line. The center conductor of each of the separate coaxial filter sections may have a plurality of inductive spokes extending outwardly toward the cylindrical outer casing, or the adjacent radial vanes, and each of the inductive spokes may be terminated by a series-connected switching diode with its own separate source of bias to electrically connect or disconnect it to or from the corresponding casing or vane. This provides the combination of two or more variable frequencies in a common output.