Design of a sharp response low-pass filter : through comparison of microwave design software

Abstract: The aim of this thesis is to do a research about three microwave design software packages and evaluate them with the purpose of getting the sharpest filter as possible and also know which one is more efficient in this task. In order to achieve this purpose we designed, simulated and tried to manufacture the same low-pass filter (using microstrip lines) in different software. This way we are able to compare features as the S-parameters of the filters, the possibilities they give us, how easy to use they are, how long takes us to run a simulation, how much deviation they have in the simulations and how much deviation we get in the measurements of the manufactured filters.   The filter has to be a low-pass filter with the cut off frequency at 1.8 GHz and a minimum attenuation of -26dB at 4.6 GHz.   The next step will be design of the 3 filters with the 3 different software. Once we have done the designs we are ready to do simulations and manufacture them in order to evaluate which one of them is more accurate and give us the best response.   To do the measurements we used a Vector Network Analyzer, in order to get the S-parameters, and a Vector Signal Generator and a Signal Analyzer in order to check the response of the filters with real signals.   Finally, as a conclusion, evaluating all the results we got we can say that ADS is the software package that has more positive points and therefore the best suited to our needs.