Controlled Out-of-Band Rejection of Filters based on SIW with Alternating Dielectric Line Sections

Abstract

[EN] A study for managing the out-of-band rejection in a new topology of filters based on substrate integrated waveguide with alternating dielectric line sections (ADLSs) is presented in this letter. ADLS is a filtering structure consisting on line sections of the same width but with alternating air and dielectric filling. The design of the lengths of each section provides the central frequency and the bandwidth of bandpass filter response. The proper selection of the structure substrate dielectric permittivity can increase the rejection band up to 2 f(o). Moreover, the selection of the filter order (i.e., the number of sections with and without dielectric) can affect the depth of the rejection band. A study of the width and the depth of the rejection band is performed with different permittivities and orders for two different filters. Then, for validation purposes, the prototypes of both filters have been manufactured and measured.