An optimal low loss HF diplexer using helical resonators

Author

Levy, R. ; Andersen, K.J.

Author_Institution

R. Levy Associates, La Jolla, CA, USA

fYear

1992

fDate

1-5 June 1992

Firstpage

1187

Abstract

A diplexer comprising two narrowband closely spaced channels in the 164-175-MHz band having relatively low insertion loss, small size, and light weight is described. The diplexer replaces a device with dimensions of 6*10*18 in. with one of dimensions 2.2*6*6 in. This order-of-magnitude reduction in size is achieved by the use of optimal asymmetric filters each having poles placed in the other passband giving high mutual isolation, combined with the use of helical resonators giving an unloaded Q on the order of 800, which is about twice as high as previous lumped element filters. Additional out-of-band rejection is obtained by the unusual technique of introducing an additional attenuation pole in the output coupling.<>

Keywords

equivalent circuits; passive filters; poles and zeros; radiofrequency filters; resonators; 164 to 175 MHz; VHF; additional attenuation; helical resonators; low loss HF diplexer; narrowband closely spaced channels; optimal asymmetric filters; output coupling; Attenuation; Band pass filters; Ceramics; Chebyshev approximation; Hafnium; Inductors; Insertion loss; Narrowband; Passband; Resonator filters;

fLanguage

English

Publisher

ieee

Conference_Titel

Microwave Symposium Digest, 1992., IEEE MTT-S International

Conference_Location

Albuquerque, NM, USA

ISSN

0149-645X

Print_ISBN

0-7803-0611-2

Type

conf

DOI

10.1109/MWSYM.1992.188210

Filename

188210