#Single stub matching smith chart pdf
That is, if the line reactance is inductive, the series stub’s reactance is capacitive.EC8651 Transmission Lines and RF Systems MCQ Multi Choice Questions, Lecture Notes, Books, Study Materials, Question Papers, Syllabus Part-A 2 marks with answers EC8651 Transmission Lines and RF Systems MCQ Multi Choice Questions, Subjects Important Part-B 16 marks Questions, PDF Books, Question Bank with answers Key And MCQ Question & Answer, Unit Wise Important Question And Answers, One Mark Question With Answers, Choose The Best Answer.ĭownload link is provided for Students to download the Anna University EC8651 Transmission Lines and RF Systems MCQ Multi Choice Questions, Lecture Notes, Books, Study Materials, Question Papers, Syllabus Part A 2 marks with answers & Part B 16 marks Question, Question Bank with answers, MCQ Question & Answer, Unit Wise Important Question And Answers, One Mark Question With Answers, Choose The Best Answer. Then the reactance of the series stub used for matching is:Ĭlarification: The reactance of the series stub is negative of the reactance of the line at the point at which it has to be matched. In series stub matching, if the normalized impedance at a point on the transmission line to be matched is 1+j1.33. Hence, there is a dip at that point of the curve.ġ0. There is a dip at this point of the curveĬlarification: Since the plot is frequency v/s reflection co-efficient, after impedance matching the reflection co-efficient will be zero or minimum. There is a peak at this point of the curveī. After impedance matching, if a graph is plot with frequency v/s reflection co-efficient of the transmission line is done, then at the frequency point for which the design is done, which of the following is true?Ī. Then the normalized susceptance of the stub used for shunt stub matching is:Ĭlarification: When shunt stubs are used for impedance matching between a load and transmission line, the susceptance of the shunt stub must be negative of the line’s susceptance at that point for impedance matching.ĩ. If the normalized admittance at a point on a transmission line to be matched is 1+j1.47. Taking the reciprocal of impedance, normalized load admittance is 0.3+j0.4.Ĩ. For impedance matching using shunt stubs, admittance is used. What is the normalized admittance obtained so as to plot it on smith chart?Ĭlarification: To impedance match a load to a characteristic impedance of the transmission line, first the load has to be normalized. Design of 2 single-stub shunt tuning networks to match this load to a 50Ω line is to be done. Co-axial lines cannot be impedance matchedĬlarification: 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.ħ. For co-axial lines and waveguides, _ is more preferred.ĭ. Then the stub reactance is chosen as –jX resulting in a matched condition.Ħ. Admittance at a point on the transmission lineĬlarification: In series sub matching, the distance‘d’ is selected so that the impedance, Z seen looking into the line at a distance‘d’ from the load is of the form Zₒ+jX. Voltage at a point on the transmission lineĬ. Impedance of the transmission line at a pointī. For series stub matching, the parameter used for matching is:Ī. Then the stub susceptance is chosen as –jB, resulting in a matched condition.ĥ. In shunt stub matching, the key parameter used for matching is:Ĭlarification: In shunt stub tuning, the idea is to select d so that the admittance Y, seen looking into the line at distance d from the load is of the form Yₒ+jB. Distance of the stub from the generatorĬlarification: Reactance or susceptance of the matching stub must be known before it used for matching, since it is the most important parameter for impedance matching between the load and the source.Ĥ. Susceptance or reactance provided by the stubĬ.
The two adjustable parameters in single stub matching are distance‘d’ from the load to the stub position, and _Ī. Hence, shunt stubs are preferred for strip and microstrip lines.ģ.
It can be fabricated as a part of transmission line mediaĬlarification: Single stub matching does not involve any lumped elements, it can be fabricated as a part of transmission media and it also involves to adjustable parameters namely length and distance from load giving more flexibility.Ĭlarification: Since microstrip and strip lines are simple structures, impedance matching using shunt stubs do not increase the complexity and structure of the transmission line. The major advantage of single stub tuning over other impedance matching techniques is:ī.
Microwave Engineering Multiple Choice Questions on “Single Stub Matching”.ġ.