Octave-Wcalc: coupled_microstrip_syn
Description: Wcalc: A transmission line calculator
Keywords: coupled microstrip, coupled microstrip analysis, coupled microstrip synthesis, microstrip, microstrip analysis, microstrip synthesis, stripline, stripline analysis, stripline synthesis,

| Octave-Wcalc: coupled_microstrip_syn coupled_microstrip_syn - Coupled microstrip transmission line synthesis ## SYNOPSIS [w_out, s_out, l_out] = coupled_microstrip_syn(z0, k, z0e, z0o, w, s, h, l, tmet, rho, rough, er, tand, f, flag) ## PARAMETERS ### INPUT PARAMETERS z0 : desired characteristic impedance (Ohms) k : desired coupling coefficient z0e : desired even mode characteristic impedance (Ohms) z0o : desired odd mode characteristic impedance (Ohms) w : width of coupled microstrip line (meters) s : spacing between coupled microstrip lines (meters) h : substrate thickness (meters) l : length of coupled_microstrip line (meters) tmet : metal thickness (meters) rho : resistivity of wire (relative to copper) rough : conductor surface roughness (meters-rms) er : substrate relative permitivitty tand : substrate loss tangent f : synthesis frequency (Hz) flag : indicates which parameters should be optimized flag=0 : synthesize based on characteristic impedance and coupling coefficient flag=1 : synthesize based on even and odd mode characteristic impedances ### OUTPUT VALUES w_out : calculated metal width s_out : calculated gap l_out : calculated metal length ## DESCRIPTION Function to synthesize the physical dimenstions of a coupled microstrip transmission line to achieve a desired characteristic impedance and electrical length. The desired characteristic impedance and some of the physical dimensions of the coupled_microstrip line are given as inputs and the remaining dimensions are calculated. The line may be specified either in terms of an even mode and odd mode characteristic impedance or a characteristic impedance and coupling coefficient. The model accounts for dispersion (frequency dependent propagation velocity). ``
                  |<--W-->|<-S->|<--W-->|
                   _______       -------
                  | metal |     | metal | <- rho,rough
        ----------------------------------------------
       (  dielectric                         /|\     (
        )   er,tand                       H   |       )
       (                                     \|/     (
        ----------------------------------------------
        XXXXXXXXXXXXXXXXXX ground XXXXXXXXXXXXXXXXXXXX
## EXAMPLE
     % mils to meters conversion factor
    sf=25.4e-6;
     % desired impedance
    z0=75;
     % desired coupling
    k=0.3;
     % desired electrical length (degrees)
    elen=90;
     % width (we'll synthesize this)
    w=0;
     % spacing (we'll synthesize this)
    s=0;
     % height
    h=15*sf;
     % length
    l=1100*sf;
     % metal thickness
    tmet=1.4*sf;
     % resitivity of copper
    rho=1.72e-8;
     % metal surface roughness
    rough=0.05*sf;
     % relative dielectric constant
    er=4.5;
     % loss tangent
    tand=0.01;
     % frequency
    f=2.4e9;
     % synthesize from z0 and k (instead
    flag=0;
     % of z0e and z0o)

    [w_out,s_out,l_out] = ...
        coupled_microstrip_syn(z0,k,elen,w,s,h,l,tmet,rho,rough,er,tand,f,flag);
    disp(sprintf('w=%8.4g mils, s=%8.4g mils, l=%8.4g mils',w_out/sf,s_out/sf,l_out/sf));
## SEE ALSO air_coil_calc air_coil_syn coax_calc coax_syn coupled_microstrip_calc coupled_microstrip_syn ic_microstrip_calc ic_microstrip_syn microstrip_calc microstrip_syn stripline_calc stripline_syn ## AUTHOR Dan McMahill ## BUGS None known Return to the Octave-Wcalc page.
Information
About Wcalc Reporting bugs Current projects Obtaining Wcalc Technical Notes Wcalc F.A.Q. Wcalc Home
Models
Air Core Solenoid Inductor Coaxial Transmission Line Coupled Microstrip Integrated Circuit Microstrip Microstrip Stripline
Frontends
CGI-Wcalc (Web Interface) GTK-Wcalc (GUI Interface) MEX-Wcalc (Matlab Interface) Octave-Wcalc (Octave Interface) SCI-Wcalc (Scilab Interface) STDIO-Wcalc (Simple stdio Interface)
Misc. Info.
Permeabilities Permitivities Resistivities Unit Conversion Factors Wire Sizes