## Re: [Qucs-devel] PI and T matching networks

 Re: [Qucs-devel] PI and T matching networks From: Stefan Jahn - 2007-02-22 11:47:48 ```Am Mi, 21.02.2007, 19:51, schrieb Erasmo Alonso Iglesias: > Hello, Hi Erasmo! > I will comment the advantages of a PI/T topology in comparison with a L > topology... > On one hand, if we consider an output resistance, a L matching network and > an input resistance, the designer can't decide the bandwidth (or the Q > factor) of the matching, because Q factor using the L network is set only > by > the output resistance and the input resistance. On the other hand, if we > consider an output resistance, a PI/T matching network and an input > resistance, the designer can decide the bandwidth (or the Q factor) of the > matching, because Q factor using the PI/T network depends on the output > resistance, the input resistance and an arbitrary virtual resistance. > The PI/T matching network can be studied as a first L matching network, > connected among the output resistance and the virtual resistance, and a > second L matching network, connected among the virtual resistance and the > input resistance. Then, there are four types of PI/T matching networks: > Low > pass-Low pass, High pass-High Pass, Low Pass-High Pass and High Pass-Low > pass, according to the two types of the two L networks that form it. > I think it would be very useful to use a tool which generates a the PI/T > matching network from the central frequency, the bandwidth, the topology > (PI > or T) and the type (LP-LP, HP-HP, LP-HP, HP-LP). > I hope that you have understood my commentaries, greetings :) Thank you very much for your explanations. Makes perfect sense. I consider it a good thing as well... Probably Michael can put that into the GUI someday... Can you probably write a latex-document describing the function and computation of those matching networks? Thanks, Stefan. ```

 Re: [Qucs-devel] PI and T matching networks From: Stefan Jahn - 2007-02-21 13:43:33 ```Am Di, 20.02.2007, 01:11, schrieb Erasmo Alonso Iglesias: > Hello, Hi there, > I write you this email because I have been programming two functions that > could be interesting in order to improve the Qucs. One of them calculates > a > PI matching network and the other calculates a T matching network. I don't > know how to program the GUI, despite I send you the file containing the > code > of the functions... Thanks for the code. Currently we a matching tool which computes L-networks for input and/or output matching. Can you tell the advantages of a T/PI topology? Thanks in advance, Stefan. ```
 Re: [Qucs-devel] PI and T matching networks From: Stefan Jahn - 2007-02-22 11:47:48 ```Am Mi, 21.02.2007, 19:51, schrieb Erasmo Alonso Iglesias: > Hello, Hi Erasmo! > I will comment the advantages of a PI/T topology in comparison with a L > topology... > On one hand, if we consider an output resistance, a L matching network and > an input resistance, the designer can't decide the bandwidth (or the Q > factor) of the matching, because Q factor using the L network is set only > by > the output resistance and the input resistance. On the other hand, if we > consider an output resistance, a PI/T matching network and an input > resistance, the designer can decide the bandwidth (or the Q factor) of the > matching, because Q factor using the PI/T network depends on the output > resistance, the input resistance and an arbitrary virtual resistance. > The PI/T matching network can be studied as a first L matching network, > connected among the output resistance and the virtual resistance, and a > second L matching network, connected among the virtual resistance and the > input resistance. Then, there are four types of PI/T matching networks: > Low > pass-Low pass, High pass-High Pass, Low Pass-High Pass and High Pass-Low > pass, according to the two types of the two L networks that form it. > I think it would be very useful to use a tool which generates a the PI/T > matching network from the central frequency, the bandwidth, the topology > (PI > or T) and the type (LP-LP, HP-HP, LP-HP, HP-LP). > I hope that you have understood my commentaries, greetings :) Thank you very much for your explanations. Makes perfect sense. I consider it a good thing as well... Probably Michael can put that into the GUI someday... Can you probably write a latex-document describing the function and computation of those matching networks? Thanks, Stefan. ```