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Comparison of the transient and the harmonic balance method .

 analysis and optimization of an amplifier depending on the impedances presented at the harmonic frequencies

Présentation CAO

•Yassine BAR!•Abdel"ader #A$!R%

•&r &ichel Campo'ecchio

$irected by ( 

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 I. comparing the transient and the harmonic balance simulation.1. Time domain analysis (Transient simulation).

•  Principle

•  Exemple of a simulation.

• Conclusion.

2. Harmonic Balance.

•  principle.

•  Exemple of a simulation.

• Conclusion.

 II. Determining the optimum harmonic loads for a power amplifier.

1. circuit analysis with loc!s of impedances and ideals filters.2. "ynthesis and optimi#ation of the matchin$ circuit dependin$ on the desired

impedances.

%. Comparison the results

➢Summary 

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Time domain analysis (Transient simulation)

Principle :

The Transient Simulation solves a set of integro-differential equations

that express the time dependence of the currents and voltages of the

circuit. The result of such an analysis is nonlinear with respect to time.

e(t)L

(i)i

!

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The Algorithm of résolution:

 x"  #(x") $ " calculation of x! #(x!) $ " %x&'n-!

% calculation of xn #(xn) $ "

Newton

Raphson

Newton

RaphsonNewton

Raphson

If yes EndIf yes

End If yes 

End

'

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 Limits of the transient analysis in the ! domain

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 "#emple of a transient simulation:

f!$ *!+ ,h f'$*'+ ,h Tstep$ $"*""!'! nsec

/

1

10 xf  2

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 esults :

➢0ven if the circuit is relatively simple * it too& the simulator !" min and

,o of data to simulate it. The results are given in the time domain. The simulator sweep all the response of the circuit from the transitional

state to the steady state

+

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 II$ %armonic &alance :

1armonic 2alance is a frequency-domain analysis technique for

o2taining the steady state  solution of nonlinear circuits and systems.calculates the magnitude and phase of voltages or currents in a potentially

nonlinear circuit.

3

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 Algorithm of resolution :

Ta&en from 4gilent5s documentation.

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f!$ *!+ ,h f'$*'+ ,h harmonics per tones.

 "#emple of a circuit analysed with a %armonic balance

simulation :

!"

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 esults :

The results are computed in the frequency domain. 6o transitional state. 7omparing to the transient simulation * the 18 simulation too& !+ seconds and !/ 9o.

!!

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➢

'onclusion : 

•The transient simulation is very consuming of time and data in

the # domain.

•  :n the case of periodic # signals * the harmonic 2alance is more

efficient than the transient simulation.

 ● 1owever* the harmonic 2alance simulation is limited 2y the num2er of

harmonics.

 ●

The transient simulation is necessary in the case of aperiodic signals orif we need to see the transitional state.

!'

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➢The two most important parameters in the conception

of a power amplifier are;

  The linearity.

 The efficiency.

 II$Analye and optimiation of a power amplifier 

Context :

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 II. Determining the optimal harmonic loads:

7ircuit analysis with the ideals impedance 2loc&s and filters

!

#ilters

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 4n impedance port that present either a short circuit or open circuit depending

on the frequency..

RES= OC if freq<fc else sc endif 

•1igh pass filter;

!/

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 esults of the simulation with impedance blocs :

!+

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synthesis and optimiation of the matching circuit depending

on the desired impedances.

!<

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*ptimiation of the matching circuit

!3

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 +imulation with the matching circuit and ,erification

!

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!=

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Thank you for your atenon