Small Size Dual-Band Bandpass Filters with Multiconductor Transmission Lines and Shunt Open Stubs

Abstract

A dual-band bandpass filter consisting of multiconductor transmission lines (MTL) and shunt stubs has been designed. The used topology, based on the interconnection of two identical MTL and a shunt open stub, has a frequency response that can be modelled by using the generalized Chebyshev functions. A prototype of a 4 fingers-MTL is manufactured and measured and a good agreement between analytical and measured results is obtained. Furthermore, it is easy to get a design criterion that enables getting good responses varying just a few parameters.

Synthesis of Dual-Band Bandpass Filters With Short-Circuited Multiconductor Transmission Lines and Shunt Open Stubs

“…The analytical solution of this quartic equation 23, using an efficient algorithm proposed in [33], is described in Appendix B. Consequently, once the specifications of the dual-band bandpass filter are known, equations (22a) and (22b) can be used along with (23) to determine the design parameters of the filter. values for prototype I, depending on the fractional bandwidth (FWB) and the frequency ratio (r), calculated using (19).…”

“…Step 5: Use (19) or (22) and (24), depending on the chosen prototype, to calculate the required values of Z 0 a , c and Z 0 b . Finally, verify that the accomplished values are physically achievable by the manufacturing process.…”

“…For prototype I, the center frequency was f 0 = 3.9 GHz, using the analytical equation (19) to choose its parameters. For the two filters of prototype II, the center frequency was set to be f 0 = 2 GHz, using (22a), (22b) and (23).…”

“…In this work, two topologies of dual-band planar bandpass filters based on series short-circuited multiconductor transmission lines (MTLs) and shunt open stubs are proposed and analyzed through analytical equations. Previously, one of these had been used by Pérez-Escribano et al [19] for a design, without making a deep analysis. By using the proposed architectures, dual-band filters with one or two poles in each band can be achieved.…”

Diseño e Implementación de un Filtro Multibanda de 2 secciones para Comunicaciones Móviles con Líneas de Transmisión y Stubs en Abierto

“…al momento de implementar el filtro. (Shaman, 2007), (Pérez-Escribano, 2018), (Girbau, 2009) Una de las técnicas de RF más populares para el diseño de filtros es la técnica de interferencia de señales, que consiste en usar líneas microstrip, ya que, estas tienen algunas de sus líneas de campo en la región dieléctrica entre el conductor de la línea y el plano de tierra, y otra fracción de campo en la región de aire por encima del sustrato. (Gómez-García, 2005), (Xu, 2010), (Ketkuntod, 2015) Por esta razón, en el presente artículo se estudia el uso de líneas microstrip (MTLs.)…”