MATLAB: How to construct an R-L-R type filter using RFTOOL in RF Toolbox 2.1 (R2007a)

RF Toolboxrlr

I am using RF Tool to analyze some data. I need to construct an R-L-R circuit filter, and I would like to know how to do this.

Best Answer

There are two ways to create an R-L-R type circuit. The first is using the command line and the other one is using the rftool library.

The following code demonstrates an example of how to construct an R-L-R type circuit in a MATLAB file (or in command line)

tx1=rfckt.microstrip('EpsilonR',4.34,'Width',4.3e-4,'Height',1e-3);
analyze(tx1,1.5e9);
tx1z0=getz0(tx1);
Rtop=rfckt.shuntrlc('R', 100);
Lmiddle=rfckt.shuntrlc('L', 30e-9);
Rbottom=rfckt.shuntrlc('R', 100);
h=rfckt.series('ckts',{Rtop, Lmiddle, Rbottom});
rlr_peaking=rfckt.cascade('ckts',{tx1,h});
analyze(rlr_peaking, 5e6:5e6:3e9,100,100,100);
plot(rlr_peaking,'S21')

Refer to the attached file rlr_peaking_filter.rf which demonstrates how to create an R-L-R type filer using the RF Tool interface.

Related Solutions

MATLAB: Are there no examples in the documentation of the PLOT function for “rfckt.cascade” objects in the RF Toolbox 2.3 (R2008a)

Examples on the PLOT function of the "rfckt.cascade" object are missing in the documentation.

Here is a basic example on how to use the plot the analysis results (S-parameters) of a tee circuit:

R1 = rfckt.seriesrlc('R',26);  %Series

R2 = rfckt.shuntrlc('R',35);  %Shunt
R3 = rfckt.seriesrlc('R',26);   %Series
tee=rfckt.cascade;  % Creating a cascade circuit
tee.Ckts={R1,R2,R3};
freq=[1e6,2e6];   %Assigning frequency for analysis
analyze(tee,freq);   
   % To plot the s21 and s11 parameters on a Linear scale
plot(tee,'s21','s11','Magnitude (linear)')

MATLAB: How to measure the group delay of a 2-port series connection in SimRF 3.0.2 (R2011a)

For such analysis the recommendation is to use functions within the RF Toolbox.Within RF Toolbox one can use rfckt.series or rfcket.cascade depending on the type of connection of interest. The process for determining the group delay is similar for either one you choose.

For example:

    ckt1 = read(rfckt.passive,'file1.s2p');
    ckt2 = read(rfckt.passive,'file2.s2p');

Then combine the circuits using either of the following:

    combined = rfckt.series('Ckts',{ckt1,ckt2});

    combined = rfckt.cascade('Ckts',{ckt1,ckt2});

Now you can analyze for the group delay, but will need a vector of frequencies:

    analyze(combined,logspace(8,10,21))

To plot the results:

    plot(combined.AnalyzedResult.Freq,combined.AnalyzedResult.GroupDelay)

Best Answer

Related Solutions

MATLAB: Are there no examples in the documentation of the PLOT function for “rfckt.cascade” objects in the RF Toolbox 2.3 (R2008a)

MATLAB: How to measure the group delay of a 2-port series connection in SimRF 3.0.2 (R2011a)

Related Question