Design of RF filters with high selectivity on monolithic ceramic blocks

The paper presents the results of the development of quasielliptic filters on monolithic ceramic blocks. A circuit analysis of equivalent filter circuits is carried out using the coupling matrix method. A novel topology of a monolithic filter is being studied with the aim of obtaining increased frequency-selective properties due to the implementation of the attenuation poles. High cross-coupling values on ceramic monoliths with large inner metalized holes were obtained. The engineering method of adjusting the frequency position of the attenuation poles by trimming capacitive stubs is realized. Based on the performed analysis, as well as electromagnetic modeling, a monolithic ceramic filter was manufactured. The measurements results of the S-parameters for obtained models are presented