Integración de múltiples stubs en filtros de saltos de impedancias de alta selectividad

Rectangular waveguide commensurate-line stepped-impedance bandpass filters have been shown to have an increased fabrication robustness using conventional CNC milling. In this paper, their frequency response is improved by adding multiple transmission zeros at fully-controlled positions around the passband. The technique starts with the design of the filter without transmission zeros and only requires that one of the filter sections is slightly redesigned, while the rest keep unaltered, when lambda_g/¿¿ and 3*lambda_g/¿¿ stubs are included in the section to increase the overall filter selectivity around the passband. The design example is a 7th-order Chebyshev bandpass filter in Ku-band.