Multilayer microstrip closely-spaced-channel wideband diplexer with highly-selective fourth-order filtering responses

A type of multilayer microstrip diplexer with highlyselectivewidebandfiltering channels is reported. Its closely-spaced fourth-order passbands are attributed to two circuit parts: (i) two third-order quasi-elliptic-type microstrip-to-microstrip wideband vertical transitions and (ii) a shunt two-stub...

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Detalles Bibliográficos
Autores: Yang, Li|||0000-0002-1264-4810, Gómez García, Roberto|||0000-0001-9132-6927
Tipo de recurso: artículo
Fecha de publicación:2022
País:España
Institución:Universidad de Alcalá (UAH)
Repositorio:e_Buah Biblioteca Digital Universidad de Alcalá
Idioma:inglés
OAI Identifier:oai:ebuah.uah.es:10017/51787
Acceso en línea:http://hdl.handle.net/10017/51787
https://dx.doi.org/10.1109/TCSII.2022.3173910
Access Level:acceso abierto
Palabra clave:Bandpass filter (BPF)
Diplexer
Microstrip filter
Multilayer circuit
Multiplexer
RF/microwave circuit
Transmission zero (TZ)
Vertical transition
Wideband circuit
Telecomunicaciones
Telecommunication
Descripción
Sumario:A type of multilayer microstrip diplexer with highlyselectivewidebandfiltering channels is reported. Its closely-spaced fourth-order passbands are attributed to two circuit parts: (i) two third-order quasi-elliptic-type microstrip-to-microstrip wideband vertical transitions and (ii) a shunt two-stub dual-band bandpass filter (BPF) junction printed on the top layer. The two microstrip vertical transitions are developed by means of open-/short-circuitended microstrip lines and slotline stepped-impedance resonators (SIRs), respectively, and they correspond to the constituent lower and upper channels. The shunt dual-band BPF junction produces one additional transmission pole and one more pair of close-topassband transmission zeros (TZs) for each channel to further increase their filtering selectivity. The RF theoretical foundations and design procedure of the engineered broadband diplexer are detailed. For practical-validation purposes, a proof-of-concept prototype of two-layer fourth-order microstrip wideband diplexer is simulated, manufactured, and tested. Its measured lower and upper channels has two closely-spaced sharp-rejection passbands with center frequencies of 1.496 GHz and 2.759 GHz and 3-dB fractional bandwidths of 62.83% and 24.83%, respectively, while featuring power-isolation levels above 27.39 dB from 0.5 to 4 GHz.