1. Outline of discussion DIRECT MODELING APPROACH
How small-signal variations in the switching frequency affect the spectrum of the switch network output voltage vs1(t)
Passing the frequency-modulated voltage vs1(t) through the tank transfer function H(s) leads to amplitude modulation of the output voltage v(t)
How to recover the envelope of the output voltage and determine the small-signal control-to-output-envelope transfer function Genv(s)
PHASOR TRANSFORMATION APPROACH
Equivalent circuit modeling via the phasor transform
PSPICE simulation of Genv(s) using the phasor transform

2. 1. Spectrum of vs1(t)

5. Spectra of frequency-modulated signal

8. Spectra of frequency-modulated signal via Bessel functions

11. Dynamic analysis of resonant inverters

13. Assumptions so far

15. 2. Effect of the tank transfer function
narrowband

16. One way

17. Phasor analysis

20. Total output voltage and envelope

21. Intepretation: time-varying phasor representation of output voltage

22. 3. Extract expression for envelope

23. Square and linearization

24. Square root and linearization

25. Result: Small-signal expression for envelope

26. The transfer function Genv(s)