# Single Stub Matching MCQ’s

This set of RF & Microwave Circuit Design Multiple Choice Questions & Answers (MCQs) focuses on “Single Stub Matching”.

1. Shunt stubs are preferred for:
a) Strip and microstrip lines
b) Coplanar waveguides
c) Circular waveguide
d) Circulators

2. The two adjustable parameters in single stub matching are distance‘d’ from the load to the stub position, and _________
a) Susceptance or reactance provided by the stub
b) Length of the stub
c) Distance of the stub from the generator
d) None of the mentioned

3. The major advantage of single stub tuning over other impedance matching techniques is:
a) Lumped elements are avoided
b) It can be fabricated as a part of transmission line media
c) It involves two adjustable parameters
d) All of the mentioned

4. In shunt stub matching, the key parameter used for matching is:
a) Admittance of the line at a point
c) Impedance of the stub

5. For co-axial lines and waveguides, ________ is more preferred.
a) Open circuited stub
b) Short circuited stub
c) Slotted section
d) Co-axial lines cannot be impedance matched

6. If the normalized admittance at a point on a transmission line to be matched is 1+j1.47. Then the normalized susceptance of the stub used for shunt stub matching is:
a) 1Ω
b) 1.47 Ω
c) -1.47 Ω
d) -1 Ω

7. For series stub matching, the parameter used for matching is:
a) Impedance of the transmission line at a point
b) Voltage at a point on the transmission line
c) Admittance at a point on the transmission line

8. For a load impedance of ZL=60-j80. Design of 2 single-stub shunt tuning networks to match this load to a 50Ω line is to be done. What is the normalized admittance obtained so as to plot it on smith chart?
a) 1+j
b) 0.3+j0.4
c) 0.4+j0.3
d) 0.3-j0.4

9. 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?
a) There is a peak at this point of the curve
b) There is a dip at this point of the curve
c) The curve is a straight line
d) Such a plot cannot be obtained

10. In series stub matching, if the normalized impedance at a point on the transmission line to be matched is 1+j1.33. Then the reactance of the series stub used for matching is:
a) 1 Ω
b) -1.33 Ω
c) -1 Ω
d) 1.33 Ω