Mex-Wcalc: coax_calc
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,

| Mex-Wcalc: coax_calc coax_calc - Coaxial transmission line analysis ## SYNOPSIS [L, R, C, G, lc, ld, fc, em] = coax_calc(a, b, c, t, rho_a, rho_b, er, tand, len, f) ## PARAMETERS ### INPUT PARAMETERS a : radius of inner conductor (meters) b : inner radius of outer conductor (meters) c : offset of the inner conductor from the center (meters) t : thickness of shield (meters) rho_a : resistivity of inner conductor (ohms/meter) rho_b : resistivity of outer conductor (ohms/meter) er : relative permitivitty of dielectric tand : loss tangent of dielectric len : physical length of line (meters) f : analysis frequency (Hertz) ### OUTPUT VALUES L : calculated inductance per length (Henries/meter) R : calculated resistance per length (Ohms/meter) C : calculated capacitance per length (Farads/meter) G : calculated conductance per length (Siemens/meter) lc : conductor loss (dB/meter) ld : dielectric loss (dB/meter) fc : TE10 cutoff frequency (Hz) em : Max Electric Field (Volts/meter) ## DESCRIPTION Function to analyze the electrical characteristics of a coaxial transmission line. The physical dimensions of the line are given as inputs and the characteristic impedance and incremental circuit model elements are calculated. ## EXAMPLE
     % mils to meters conversion factor
    sf=25.4e-6;
     % radius of inner conductor
    a=10.0*sf;
     % inner radius of outer conductor
    b=100.0*sf;
     % offset of inner conductor
    c=0*sf;
     % thickness of outer conductor
    t=5.0*sf;
     % resistivity of inner conductor
    rho_a=3.5e-8;
     % resistivity of outer conductor
    rho_b=rho_a;
     % relative permitivitty of dielectric
    er=9.5;
     % dielectric loss tangent
    tand=0.01;
     % length of line
    len=1.0;
     % 100 MHz operation
    f=100e6;
    [z0,elen,loss,L,R,C,G,lc,ld,fc,em] = coax_calc(a,b,c,t,rho_a,rho_b,er,tand,len,f);
    disp(sprintf('z0   = %g Ohms',z0));
    disp(sprintf('elen = %g degrees',elen));
    disp(sprintf('loss = %g dB',loss));
    disp(sprintf('L    = %g H/m',L));
    disp(sprintf('R    = %g Ohms/m',R));
    disp(sprintf('C    = %g F/m',C));
    disp(sprintf('G    = %g S/m',G));
    disp(sprintf('Conductor loss  = %g dB/m', lc));
    disp(sprintf('Dielectric loss = %g dB/m', ld));
    disp(sprintf('TE10 cutoff     = %g GHz', fc/1e9));
    disp(sprintf('Max E field     = %g kV/m', em/1e3));
## 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 MEX-Wcalc page.
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Models
Air Core Solenoid Inductor Coaxial Transmission Line Coupled Microstrip Integrated Circuit Microstrip Microstrip Stripline
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Misc. Info.
Permeabilities Permitivities Resistivities Unit Conversion Factors Wire Sizes