single stub and double stub matching using smith chart pdf

In that case, a distance must be allowed between the first stub and the load.

The minimum value of this distance is not easily found on a Smith chart, nor is analytical formulas available for the determination of this minimum distance. In our case study the distance between load and first stub is not zero. Once the load impedance and frequency is taken into consideration with the use of it all the parameters of the double stub matching can be determined. įig.1 shows the entire procedure of the system. Once the load impedance and the distance between two stubs are known all the parameters of the double stub matching can be determined. Parameters such as lengths of two stubs and minimum length required between first stub and load can be computed by known parameters. L l= distance between first stub and loadĪBCD parameters can be used for transmission line network LB = length of second stub L=distance between the stubs With the use of the ABCD-matrix (the chain- parameter) representation for a transmission-line network an analytical solution for the general double-stub impedance-matching problem can be obtained.įrom the fig, 2 load admittance YL is to be matched to a main line with characteristics admittance YO. Representation, because they can be used easily in cascade connection.įrom eq. Then the equation for the normalized admittance at terminalįrom the above equation the final lengths of both the stubs can be written as ĪBCD matrices for a shunt stub having a normalized input susceptance b and for a section 1 of a lossless transmission line are respectivelyĪBCD matrix for the combination of transmission line of length L and the shunt stubs at ports AA and BB.Ĭ D j cosl-b2sinl 6 and 7 value of b1 and b2 can be calculated. Following system tools of LabVIEW are being utilized in The normalized input admittance at terminals BB' is Ĭosl-b2sinl (g' +jb' )+jĪ.

Single stub and double stub matching using smith chart pdf