next up previous
Next: 31/01/2003 by Pankaj Kumar Up: 21/1/2003 by Jatiner Mohan Previous: 21/1/2003 by Jatiner Mohan

Describing Function Sinusoidal I/P

$\displaystyle N(A,w)$ $\displaystyle = \frac{A_{1}{(A,w)}}{A} e^{j\phi(A,w)}$ (3.1)
  $\displaystyle = n_{p}+jn_{q}$ (3.2)
$\displaystyle n_{p}$ $\displaystyle = \frac{1}{\pi A} \int^{2\pi}_{0}{y \sin \psi d\psi}$ (3.3)
$\displaystyle n_{q}$ $\displaystyle = \frac{1}{\pi A} \int^{2\pi}_{0}{y \cos \psi d\psi}$ (3.4)

Static non-linearity not depends upon $ w$ Mulivalue function are known as memory functions For memory less static function $ n_{q}=0$ Memoryless-static-odd $ f(-x)=-f(x)$

$\displaystyle n_{p}$ $\displaystyle = \frac{4}{\pi A} \int^{\frac{\pi}{2}}_{0}y \sin \psi d \psi$ (3.5)
$\displaystyle N(A)$ $\displaystyle = \frac{2j}{\pi A} \int^{\pi}_{0}y (A\sin \psi)e^{-j\psi} d\psi$ (3.6)
$\displaystyle N(A)$ $\displaystyle = \frac{2j}{\pi A} \int^{\psi_1}_{0}{-De^{-j\psi} d\psi +\int^{\pi}_{\psi_{2}}{-De^{-j\psi} d\psi}}$ (3.7)
$\displaystyle N(A)$ $\displaystyle = \frac{2D}{\pi A}[\cos \psi_2+\cos \psi_1-j(\sin \psi_2+\sin \psi_1)]$ (3.8)
$\displaystyle A\sin \psi_{1}$ $\displaystyle = \delta(1-\epsilon)$ (3.9)

Representing $ \psi_{2}$ also

$\displaystyle N(A) = \frac{2D}{\pi A}\sqrt{1-(\frac{\delta}{a})^2(1+\epsilon)^2}+\sqrt{1-(\frac{\delta}{a})^2(1-\epsilon)^2}-j\frac{2\delta}{A}$ (3.10)


next up previous
Next: 31/01/2003 by Pankaj Kumar Up: 21/1/2003 by Jatiner Mohan Previous: 21/1/2003 by Jatiner Mohan
Vishal Mahulkar (98D10043) 2003-02-14