Mex-Wcalc: stripline

Mex-Wcalc: stripline_syn

stripline_syn - Symmetric stripline transmission line synthesis

SYNOPSIS

[w_out, h_out, l_out, er_out] = stripline_syn(z0, w, h, l, tmet, rho, rough, er, tand, f, flag)

PARAMETERS

INPUT PARAMETERS

z0 : desired characteristic impedance (Ohms)
w : width of stripline line (meters)
h : substrate thickness (meters)
l : lentgh of stripline line (meters)
tmet : metal thickness (meters)
rho : resistivity of the metalization (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=1 : synthesize the metal width
- flag=1 : synthesize the substrate thickness
- flag=2 : synthesize the substrate dielectric constant
- flag=3 : synthesize the metal length

OUTPUT VALUES

w_out : Calculated width of stripline line (meters)
h_out : Calculated height of stripline line (meters)
l_out : Calculated length of stripline line (meters)
er_out : Calculated substrate relative permitivitty of stripline line

DESCRIPTION

Function to synthesize the physical dimenstions of a single stripline transmission line to achieve a desired characteristic impedance and electrical length. The desired characteristic impedance and some of the physical dimensions of the stripline line are given as inputs and the remaining dimensions are calculated.


    XXXXXXXXXXXXXXXXX ground XXXXXXXXXXXXXXXXXXXXX
    ----------------------------------------------
   (  dielectric,er         \/           /|\     (
    )             -------   --            |       )
   (             | metal | Tmet           | H    (
    )             -------   --            |       )
   (             <---W--->  /\           \|/     (
    ----------------------------------------------
    XXXXXXXXXXXXXXXXX ground XXXXXXXXXXXXXXXXXXXXX

EXAMPLE

 % mils to meters conversion factor
sf=25.4e-6;
 % desired impedance
z0=75;
 % desired electrical length (degrees)
elen=90;
 % width (we'll synthesize this)
w=0;
 % height
h=62*sf;
 % length
l=1100*sf;
 % metal thickness
tmet=1.4*sf;
 % resitivity
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 width
flag=0;
[w_out,h_out,l_out,er_out] = ...
  stripline_syn(z0,elen,w,h,l,tmet,rho,rough,er,tand,f,flag);
disp(sprintf('w=%g mils, l=%g mils',w_out/sf,l_out/sf));
disp(sprintf('er=%g',er_out));
disp(sprintf('z0=%g ohms, length=%g degrees',z0,elen));