STUPIDSID
1 (a)
Find S-parameter of two port series network Z=100Ω and Z0=75Ω
5 M
1 (b)
Draw and explain in short test setup to measure signal to noise ratio.
5 M
1 (c)
Explain 1dB compression.
5 M
1 (d)
Explain stability circles and its importance in amplifier design.
5 M
2 (a)
Derive the transducer power gain as:\[ G_T= \dfrac {P_L}{P_{avg}}= \dfrac {|s_{21}|^2 \left ( 1- \left |\Gamma s \right | ^2 \right ) \left ( 1- \left | \Gamma L \right |^2 \right )} { \left | 1- \Gamma s \Gamma in \right |^2 \left | 1-s_{22} \Gamma L \right |^2} \]
10 M
2 (b)
For the two-port network shown below find input reflection co-efficient (Γin) and output reflection co-efficient (Γout) using signal flow graph:
10 M
3 (a)
A BJT has the following S-parameters: [ S_{11}= 0.65angle -95^{circ} S_{21}=5.0 angle 115^{circ} \ S_{12}= 0.035 angle 40^{circ} S_{22} = 0.8 angle -35^{circ} ] Is this transistor unconditionally stable? Draw input and output stability circles.
10 M
3 (b)
Determine stability of a GaAs FET that has the following S-parameter at 2GHz in a 50 Ω system both graphically and mathematically: [ S_{11}=0.89 angle -60^{circ} S_{21}=3.1angle 123^{circ} \ S_{12}=0.02 angle 62^{circ} S_{22} = 0.78 angle -27^{circ} ]
10 M
4
Design a transistor oscillator at 4GHz using FET in a common gate configuration. An inductor of values 5nH is placed in series with the gate to increase the instability. Choose a terminating network to match a 50Ω load and an appropriate tuning network. The S-parameter of the transistor are: [ S_{11}=2.18 angle -35^{circ} S_{21}=2.75 angle 96^{circ} \ S_{12}= 1.26 angle 18^{circ} S_{22}= 0.52 angle 155^{circ} \ ]
20 M
5
A power amplifier uses a GaAs FET transistor that has the following large signal S-parameters 3 Ghz in a 50Ω system:
Given: [ S_{11}= 0.62 angle 140^{circ} S_{12}=0.06 angle -10^{circ} \ S_{21}= 2.58 angle 20^{circ} S_{22}= 0.53 angle -120^{circ} \ P_{db}= 30 dbm ] Design a class A power amplifier for maximum output power. Assume ±0.5 db error in gain is allowable in our design.
Given: [ S_{11}= 0.62 angle 140^{circ} S_{12}=0.06 angle -10^{circ} \ S_{21}= 2.58 angle 20^{circ} S_{22}= 0.53 angle -120^{circ} \ P_{db}= 30 dbm ] Design a class A power amplifier for maximum output power. Assume ±0.5 db error in gain is allowable in our design.
20 M
6 (a)
Explain in detail signal ended diode Mixer. What are mixer design considerations?
10 M
6 (b)
Explain broad band microwave amplifier using balance amplifier design techniques.
10 M
Write short notes on any two:-
7 (a)
Characteristics of power amplifier
10 M
7 (b)
Microwave Resonators
10 M
7 (c)
Balanced FET Mixer.
10 M
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