Why do transmission lines Match stubs?
Stubs can be used to match a load impedance to the transmission line characteristic impedance. This distance is chosen so that at that point the resistive part of the load impedance is made equal to the resistive part of the characteristic impedance by impedance transformer action of the length of the main line.
What are the advantages of stub matching?
This is called stub matching. It has two advantages: (a) The length and characteristic impedance of the line remains unchanged. (b) Adjustable susceptance can be added in shunt with the transmission line.
What is a main condition for location of stub matching?
There are two design parameters for single stub matching: ❑ The location of the stub with reference to the load dstub. ❑ The length of the stub line Lstub. Any load impedance can be matched to the line by using single stub technique.
What is the difference between single stub matching and double stub matching?
Double stub matching is used as an alternative to single stub because in single stub the stub is placed only at specific point and that specific point may be at a wrong place where it is not needed so the double stubs used to match the load .
Why do we use short circuit stubs instead of open circuit stubs?
Short circuited stubs are preferred to open-circuited stubs because the latter are, more difficult to make and correct. made of a transmission line with a different Z0. liable to radiation from open end.
Can we have triple stub?
Triple-Stub Matching The disconnection is not physical and is achieved by simply adjusting the length of the stub to . The -stub appears open at the junction point D. C and D for double-stub matching.
Which stub is mostly preferred?
Explanation: For co-axial cables and waveguides, short-circuited stub is usually preferred because the cross-sectional area of such an open-circuited line may be large enough to radiate, in which case the stub is no longer purely reactive.
What is stub in power system?
A stub is a short-circuited section of a transmission line connected in parallel to the main transmission line. A stub of appropriate length is placed at some distance from the load such that the impedance seen beyond the stub is equal to the characteristic impedance.
Why is double stub matching used?
To overcome the drawbacks of the single-stub matching technique, the double-stub matching technique is employed. The technique uses two stubs with fixed locations. As the load changes only the lengths of the stubs are adjusted to achieve matching. stub is located at a convenient distance from the load say (Figure).
What is a Smith chart used for?
The Smith Chart is used to display an actual (physical) antenna’s impedance when measured on a Vector Network Analyzer (VNA). Smith Charts were originally developed around 1940 by Phillip Smith as a useful tool for making the equations involved in transmission lines easier to manipulate.
What is the advantage of double stub matching over single stub matching?
(ii) Double stub matching requires only the length of the stubs being changed while the position (or location) of the stubs over the transmission line can be arbitrary. This is a definite advantage over single stub matching.
What are stubs?
1 : a short part remaining after the rest has been removed or used up a pencil stub. 2 : a small part of a larger piece of printed paper (as a check or ticket) kept as a record of the purpose of the paper. stub. verb. stubbed; stubbing.