FIELD: radio engineering, communication.
SUBSTANCE: apparatus for frequency-dependent suppression of signals has two signal loops or paths connected by directional couplers, the first loop having an element such a delay element or a duplexer, the second loop having a band-stop filter, an up-converter, a down-converter, wherein each of said converters has one or more mixers and filters.
EFFECT: filtration of low frequencies with multiple frequency change in the radio frequency range, where at the filter input there is a wide dynamic range between signals in the attenuation band and the pass band.
23 cl, 11 dwg
