Modeling and Experimetal Study of Non-Reflective Microwave Filters

The paper is devoted to the study of non-reflective bandpass filters (NBPFs) of the microwave band based on coupled strip lines (SLLs) and lumped RLC elements. The distinctive feature of NBPFs is the presence of a single operating bandwidth and low reflection coefficient over a wide frequency range. The modeling and experimental study of the device have been performed. The developed sample NBPF according to the modeling data in the frequency range from 10 MHz to 6 GHz NBPF showed the required reflectionless capability, where the $S_{11}$ coefficient does not exceed minus 10 dB. The insertion loss $S_{21}$ at the center frequency of 1 GHz was minus 2.38 dB. The inverse problem of determining the frequency dependences of the RLC-circuit impedance by the output frequency characteristics of the filter was solved.