*4 January 2018*

Welcome to the new term and
good luck!

On the first day we talked
about logistics and then looked at what will be covered in
the course. Then we covered

the first pages of the script. We started with the Fourier
series. For an applet on Fourier
series computations, click here.

Try out different signals and try to predict the magnitude and
phase spectra. To plot a
function, click here.

Then we continued with the FT, looked at the Dirichlet
conditions and computed the FT of a rectangular pulse.

9 January 2018

We started with the FT, looked at the Dirichlet conditions and
computed the FT of a rectangular pulse.We compared the FS with the
FT.

We computed the FT of the exponentially decaying function. We compute the FT of the cosine and the step functions. For the last two functions

we had to introduce the delta function in more detail.

16 January 2018

We looked at the properties of the FT.

18 January 2018

We continued with Chapter 1.6. We looked at the delay line and then at the low-pass filter.

23 January 2018

We then familiarized ourselves with the graphical computation of the convolution function. Click here and here

some visualizations. We are now on p. 31.

25 January 2018

We computed y(t)=r(t)*h(t) for the delay line. We introduced the ideal low-pass filter and the physically realizable filter.

We learned about Butterworth, Bessel and Chebyshev filters.

30 January 2018

We looked at an example of a signal distortion in a filter. We intruduced the rise time of a filter and then showed via an applet the output a filter when the input is a step function. We learned about pulse dispersion in a plasma.

1 February 2018

We made an educated guess as to the phase function of the transfer function of a dispersive plasma. We talked about the sampling theorem and then about energy, power and their spectral densities.

6 February 2018

We looked at the autocorrelation functions and the cross-correlation functions and finished Chapter 1.