%0 Electronic Article
%A P.R. Rigg
%A J.E. Carroll
%K impedance level
%K broadband codirectional microwave couplers
%K power splitting couplers
%K line parameters
%K scattering parameters
%K planar comb microstrip lines
%K S-band
%K herringbone microstrip lines
%X Equations relating the scattering parameters to the line parameters of an n-line system of coupled transmission lines are applied to the design and construction of three-line broadband codirectional microwave couplers using planar comb and herringbone microstrip structures. Theoretical curves are produced for the scattering parameters of equal power splitting couplers with a range of output phase differences at the centre operating frequency. A broadband coupler is achieved with a phase difference of π radians between the output ports at the centre frequency. The bandwidth is ± 65% which is the largest so far reported for a single section uniform device. Three couplers are constructed using various dielectric materials and their performances measured using a time domain automatic network analyser (t.d.a.n.a.), a relatively new broadband microwave measurement technique. One of the couplers is designed to transform the impedance level from 50 Ω at the input to 25 Ω at the output ports. A possible application of the coupler is demonstrated in microwave GaAs. f.e.t. amplifier design and results are given for a two-device circuit operating around 3 GHz.
%@ 0143-7097
%T Three-line broadband codirectional microwave couplers using planar comb and herringbone microstrip lines
%B IEE Proceedings H (Microwaves, Optics and Antennas)
%D December 1980
%V 127
%N 6
%P 315-322
%I
%U https://digital-library.theiet.org/;jsessionid=3486ppd3edk1l.x-iet-live-01content/journals/10.1049/ip-h-1.1980.0067
%G EN