DESIGN AND MODELING OF BAND-PASS FILTERS ON COAXIAL RESONATORS FOR THE CELLULAR COMMUNICATION SYSTEMS

Abstract

The provided analysis shows the need to ensure non-interference operation of radio electronic facilities (REF) by eliminating the incompatible radio technologies in the adjacent frequency bands or by minimizing interference as far as possible. A presented example based on the cellular communication systems suggests that one of the factors influencing the size of a guard interval is the need to 'filter-out' nearby radio technologies operating in opposite directions of transmission. In such instances, filters shall be used to avoid interference. Filters will allow, in the first place, to create necessary attenuation in the reception band of the base station (BS) of nearby radio technology to suppress out-of-band and spurious emissions, furnishing by BS own transmitter; and in the second place, to create attenuation in the transmission band of nearby radio technology to reduce signals coming from BS transmitters of nearby radio technology at the input of own BS receiver. Additional high slope AFR filters may be required for both the BS transmitters and BS receivers in some frequency ranges in Ukraine. This article contains the results of modeling, designing, experimental research and testing of the band-pass electric filter with cross-links in a wide range of UHF bands (820-843 MHz and 890-915 MHz, 1920-1980 MHz and 2510-2570 MHz) using the low-frequency filter prototype method.