Contents
Matching network demo
Component values required to make an L-type matching network for a given loop antenna at various frequencies
%-------------------------------------------------------------------------- % Copyright (c) 2020 Princeton Satellite Systems, Inc. % All rights reserved. %-------------------------------------------------------------------------- % Since 2020.1 %--------------------------------------------------------------------------
Set up antenna
dAnt = 0.1; dWire = 1e-3;
Frequency-dependent parameters
f = linspace(1,8)*1e6; [l, r] = LRLoopAntenna( dAnt, dWire, f, 1 ); rL = r; xL = 2*pi*f*l;
Design matching circuit
[xS,xP,sFirst] = MatchingCircuit(50, rL, xL, +1); cS = -xS/2/pi./f; cP = -xP/2/pi./f;
Check that output impedance is correct
zL = rL + xL*1i; zS = 1i*xS; zP = 1i*xP; rCombined = zeros(size(zS)); % Elements where the correct L-type circuit has series element first: inds = find(sFirst); rCombined(inds) = zS(inds) + 1./(1./zP(inds)+1./zL(inds)); % Elements where the correct L-type circuit has parallel element first: inds = find(~sFirst); rCombined(inds) = 1./(1./zP(inds) + 1./(zS(inds)+zL(inds)));
Report
Plot2D(f/1e6,[real(rCombined);imag(rCombined)],'Frequency (MHz)',{'Resistance (\Omega)','Reactance (\Omega)'},'Verify correct effective impedance'); Plot2D(f/1e6,[xS;xP],'Frequency (MHz)',{'Series reactance (\Omega)','Parallel reactance (\Omega)'},'Reactance'); Plot2D(f/1e6,[cS;cP]*1e9,'Frequency (MHz)',{'Series capacitance (nF)','Parallel capacitance (nF)'},'Component values'); %-------------------------------------- % $Id: b2bcf84c9637d6ada4678a3964a9e7517c2441ea $
