SIDDHARTH INSTITUTE OF ENGINEERING &TECHNOLOGY:: PUTTUR

ELECTRONICS & COMMUNICATON ENGINEERING

RADIO FREQUECY INTEGRATED CIRCUITS (RFIC)

QUESTION BANK

UNIT -1: INTRODUCTION RF SYSTEMS

Essay type Questions

1. A) Give the importance of RF System in Communications and write in detail.[CO1 [L1] [8M]

B) Give the importance of LNA in RF system?[CO1] [L1][2M]

2. Discuss the basic Architectures of the RF System in detail.[CO1] [L2][10M]

3. Interprethe reflections in transmission medium of RF System. [CO1] [L3][10M]

4. A) The maximum power transfer in networks is deciding the distribution of power to other networks give the details on it. [CO1] [L3][5M]

B)State and prove theMaximum power is transfer theorem.[CO1] [L3][5M]

5. A) Write about RLC Networks with network examples[CO1] [L2][5M]

B) Derive quality factor for parallel RLC network.[CO1] [L4][5M]

6. A) Discuss the importance of matching in RF Systems.[CO1] [L2][5M]

B) Discuss how three degree of freedom is achieved in π –match. [CO1] [L4][5M]

7. Prove that three degree of freedom is achieved using T-match. [CO1] [L4][10M]

8. Draw and explain in detail about IC interconnects of capacitors.[CO1] [L5][10M]

9. Write about interconnects of resistors[CO1] [L2][10M]

10. A) Whatare the conditions for resonance in parallel RLC network.[CO1] [L2][2M]

B) What is skin effect. [CO1] [L2][2M]

C) Write the importance of matching.[CO1] [L2][2M]

D) Define 'Q' in RF SYSTEMS.[CO1] [L1][2M]

E) Write advantages of π –match over L-match.[CO1] [L2][2M]

Two Marks Questions

1)What is RF System? [CO1] [L1][2M]

2)What are the shapes are there to design RF System?[CO1] [L2][2M]

3)What is the role of RF amplifier in receivers?[CO1] [L2][2M]

4)Give the examples of RF design circuits.[CO1] [L2][2M]

5)Passive IC components having interconnections of capacitors give that cases of interconnection of capacitors [CO1] [L2][2M]

6)Explain the Hallow shape interconnection of Inductors[CO1] [L2][2M]

7)Why need Quality factor ‘Q’ in RF system?[CO1] [L2][2M]

8)Discuss the Series RLC network with circuit.[CO1] [L2][2M]

9)Get the idea of Parallel RLC network in RF circuits[CO1] [L2][2M]

10)What is matching in networks?[CO1] [L2][2M]

11) What is the importance of Maximum power transfer theorem in network? [CO1] [L2][2M]

12) What is the importance of reflection coefficient (Γ)?[CO1] [L3][2M]

13) In super heterodyne receiver what is the function of RF amplifier[CO1] [L2][2M]

14) What are the types of Resistors in interconnections?[CO1] [L2][2M]

15) Define skin depth in RF Systems[CO1] [L1][2M]

16) Write short notes on π- matching networks [CO1] [L2][2M]

17) Write short notes on T- matching networks[CO1] [L2][2M]

18) What is Square spiral inductor explain it?[CO1] [L2][2M]

19) What is Hallow spiral inductor explain it?[CO1] [L2][2M]

20) Mention the advantages of RF Systems[CO1] [L3][2M]

Objective type Questions

1. In the following which is not discipline to design RF Circuit. [ ]

a) Random signals b) CAD Tools c) Time constant d) Microwave theory.

2. In simple RF Communications Which amplifier are used [ ]

a) Single tuned amplifier b) stagger tuned amplifier c) Multistage amplifier d) Power amplifier

3) To design RF Circuit which is the shape is used [ ]

a) Pentagon b) Hexagon c)triangle d) Rectangle

4) What is the value of Centre frequency in Generic RF transceiver [ ]

a) fc = 3.4 GHz b) 2 GHz c) 2.4 GHz d) 1.4 GHz

5) In parallel RLC tank circuit the quality factor can be find as [ ]

a) Q = ω (Energy stored)/ (Power dissipated) b) Q = (Energy stored)/(Average Power dissipated)

c) Q = ω (Energy stored)/ (Average Power dissipated) d) Q = ω(Energy stored )/(Power dissipated)

6) The average power can be found as [ ]

a) Pavg = I2PK R b) Pavg = 1/2 ( I2PK R2 ) c) Pavg = 1/2 ( I PK R2 ) d) Pavg = 1/2 ( I2PK R )

7) Characteristic impedance of the parallel RLC network[ ]

a) Z0= L/C b) Z0 = √ (L/C) c) Z0 = √ ( LC ) d) Z0 = ( LC )

8) The total energy stored in a parallel RLC network [ ]

a) Etotal = 1/2 C ( IPK R ) b) Etotal = 1/2 ( I PK R )2

c) Etotal = 1/2 C ( I PK R )2d)Etotal = 1/2 C ( I PK ) 2

9) What is the quality factor for RLC parallel network?[ ]

a) Q = ω0RC b) Q = ω0 / RC c) Q = ω0C d) Q = ω0R

10) Maximum power transferred to load, if[ ]

a) ZL = Z0b) ZL > Z0c) ZL < Z0 d) ZL >Z0

11) In parallel RLC network what is ‘Q’[ ]

a) Q = ω0 LS / Rs b) Q = LS / Rs c) Q = RS / Ls d) Q = ω0 RS / Ls

12)In parallel RLC network what is LP[ ]

a) LP = (Q2 +1) / Q2 b) LP= LS [(Q2 +1) / Q2] c) LP = LS [(Q2 +1) / Q ] d) LP = LS (Q2 +1)

13) In parallel RLC network what is RP[ ]

a) RP = (Q2 +1 ) b) RP = RS (Q +1 ) c) RP = RS (Q2 +1 ) d) RP = RS

14) In parallel RLC network what is CP[ ]

a) CP = Cs( (Q ) / (Q2 +1 )) b) CP = Cs ( (Q2 ) / (Q +1 ))

c) CP = ( (Q2 ) / (Q2 +1 ) ) d) CP = Cs ( (Q2 ) / (Q2 +1 ) )

15) In L- matching circuits what is the value of RP[ ]

a) RP = LS / C b) RP = ( 1/Rs ) (LS / C) c) RP = ( 1/Rs ) ( C/ LS) d) RP = ( C/ LS)

16) In L- matching circuits what is the value of ‘Q’ [ ]

a) Q = RP / Rs b) Q = Rs / Rp c) Q = √ (Rs / Rp ) d)Q = √ (Rp / Rs )

17) The LNA adds ______noise by its own.[ ]

a) high b) low c) both d) none

18) Frequency synthesizer synchronizes to ______[ ]

a) local clockb) small clockc) global clockd)none

19) Parallel RLC network is know as ______[ ]

a) tank circuit b) filter circuitc) quality circuitd)none

20) The resistance increases owing to a phenomenon known as _____ effect[ ]

a) Active b) proximity c) skind)none

21) Another name for RFIC is______[ ]

a) circuit for cellphoneb) Cmosc)Icd)none

22) The quantity √L/C has the dimensions of resistance is called______[ ]

a) Characteristic impedance b) Input impedance c) Output impedance d) none

23) The peak energy stored in either the capacitor or inductor is [ ]

a) highb) lowc) equald) none

24) At resonance , the voltage across the network is ______[ ]

a) IinRb)RI2c)IRVd) none

25) The quality factor for series RLC network is ______[ ]

a) Q=(√L/C)/Rb) Q=(√C/L)/Rc) Q=(√C/L)/RCd) none

26) The π-match results from cascading two ______sections[ ]

a) LCb) Tc) L d) none

27) The T-match is particularly useful when the source and termination parasitics are

Primarily ______in nature[ ]

a)Capacitive b) inductivec) bothd) none

28) The total capacitance per unit area can be increased by using more than one pair of___ [ ]

a) Interconnect layersb) connect layersc) bothd) none

29) The most widely used on-chip inductor is____[ ]

a) linear planar b) circular planarc) spiral planard) none

30) The inductance of an ______spiral is a complicated function of geometry[ ]

a) planarb) arbitrary c) circulard) none

31) Maximizing the distance to the substrate minimizes the _____ capacitance between the

Inductor and the substrate[ ]

a)Earlyb) parallelc) parasitic d)none

32) The _____resistive losses are exacerbated by the skin effect[ ]

a) DC b) ACc) bothd) none

33) The consequence is a reduction in the effective cross- section ,increasing the ___ resistance [ ]

a) parallelb) seriesc) bothd) none

34)______computations based on this modified skin depth formula[ ]

a) Capacitanceb) Inductancec) Resistanced) none

35) In addition to the _____ resistive loss, capacitance to the substrate is another conspicuous

Problem of on –chip spirals[ ]

a) Seriesb) parallelc) bothd) none

36) A case of interest is the ______of a single loop of wire[ ]

a) Resistance b) Capacitancec) Inductanced) none

37) If a series RLC network with a Q of _____ is driven at resonance with a one-volt source [ ]

a) 10b) 100c) 1000d) none

38) The rule of thumb is extremely useful for rapidly estimating Q from experimental ____ data [ ]

a) Impulse b) stepc) bothd) none

39) _____ match is universal equation [ ]

a) L b) Tc) πd) none

40) In L-match ,Q is fixed at a value roughly equal to the square root of the ____ ratio[ ]

a) Capacitance b) Resistance c) Transformation d) none

SIDDHARTH INSTITUTE OF ENGINEERING &TECHNOLOGY:: PUTTUR

ELECTRONICS & COMMUNICATON ENGINEERING

RADIO FREQUECY INTEGRATED CIRCUITS (RFIC)

UNIT -2:A REVIEW OF MOS DEVICE PHYSICS

Essay type Questions

1. a. Give the advantages of MOS Technology. [L2] [CO.2][2M]

b. For N-Channel MOSFET, prove that drain current in linear region linearly changes with Vds.

[L4][CO.3][8M]

2.Derive the drain current in pentode region for N-Channel MOSFET. [L4][CO.3][8M]

3. a. Derive the characteristic impedance of ideal and lossy transmission line. [L4][CO.3][6M]

b. Derive the reflection coefficient of transmission line. [L4][CO.3][4M]

4.Illustrate Schmitt chart to estimate impedance. [L2][CO.2][10 M]

5. Illustrate how Short circuit constants (SCTs) techniqueused to estimate the bandwidth of linear

network. [L2][CO.3][10M]

6.Illustrate how Open circuit constants (OCTs) techniqueused to estimate the bandwidth of linear

network. [L2][CO.3][10M]

7. a. Define Elmore delay. [L2][CO.3][2M]

b. Describe the delay of systems in cascade in terms of moments of impulse response.

[L4][CO.3][8M]

8. a. Derive expression for overall rise time of systems in cascade using rise time addition rule.

[L4][CO.3][8 M]

b. Prove that risetime bandwidth product of first order system is 2.2. [L4][CO.3][2M]

9.a. Explainzeros as bandwidth enhancers. [L2][CO.3][5M]

b. Design the shunt-series amplifier to enhance bandwidth. [L4][CO.3][5M]

10. a. Describe how single tuned amplifier achieves narrow band amplification. [L2][CO.3][6M]

b. Describe how gain of cascaded amplifier changes with ‘n’. [L2][CO.3][4M]

Short Answer Questions

1. Explain “Conductance modulation” in MOSFET. [L1][CO.2][2M]

2. Distinguish long channel and short channel MOSFET. [L2][CO.2][2M]

3. Explain important regimes of operating frequency. [L1][CO.2][2M]

4. Define the reflection coefficient. [L3][CO.2][2M]

5. Brief the bandwidth estimation techniques. [L1][CO.3][2M]

6. Draw the circuit for shunt peaked amplifier. [L3][CO.3][2M]

7. Draw the circuit for shunt-series amplifier. [L3][CO.3][2M]

8. Define rise time. [L1][CO.3][2M]

9. Define delay of the cascading system. [L1][CO.3][2M]

10. State the relation between bandwidth and risetime for first order system . [L2][CO.3][2M]

11. Write the equation drain current in long channel MOSFET. [L1][CO.3][2M]

12. State the relation between IDand Vds in in triode region of operation. [L1][CO.2][2M]

13. Brief the open circuit time constants (OCTs) technique. [L1][CO.3][2M]

14. Brief theshort circuit constants (SCTs) techniques. [L1][CO.3][2M]

15. What is the use of smith chart in RF system. [L1][CO.2][2M]

16. Describe how bandwidth of cascaded amplifier changes with ‘n’. [L2][CO.3][2M]

17. Draw the circuit of single tuned amplifier. [L1][CO.2][2M]

18. State the bandwidth of multi stage amplifier. [L1][CO.2][2M]

19. State the role of RFin shunt series amplifier. [L1][CO.2][2M]

20.Brief about shunt series amplifier. [L3][CO.3][2M]

Objective Questions

1. MOSFET is a ______controlled device[ ]

A. Voltage B. Current C. Power D. None

2. Long channel is actually ____ electric field[ ]

A. High B. Low C. Medium D. None

3. Short channel is actually ____ electric field[ ]

A. Medium B. High C. High D. None

4. The primary high-field effect is______[ ]

A. Frequency modulation B. Current Saturation C. Voltage Saturation D. Velocity saturation

5. In long-channel devices, the saturation drain current is corresponding to ___ of the channel. [ ]

A. Pinch-off. B. Vt C. Carrier velocity D.None

6. In short-channel devices, the saturation drain current is corresponding to __of the channel. [ ]

A. Pinch-off. B. Vt C. Carrier velocity D.None

7. _____distinguishes "long-channel" from "short-channel". [ ]

A. Electric field strengths. B.VgsC.VdsD.None

8. Kirchhoff's voltage and current " laws" are used to approximate_____ regime [ ]

A. LumpedB.Distributed C. Both A and B D. None

9. ______parameter descriptions of circuits is used for ICs. [ ]

A. Distributed B. Lumped C. Both A and B D. None

10. Net magnetic charge would cause______in the magnetic field [ ]

A. Convergence B. Curl C. Divergence D. None

11. Changing magnetic field causes ______in the electric field. [ ]

A. Convergence B. Curl C. Divergence D. None

12. Reduction of "parasitics" leads to ______bandwidth[ ]

A.InfiniteB.Decrease C. Increase D. Zero

13. In ladder network the ratio of Zin to R is known as ______[ ]

A. Golden ratio B. Golden section C. A or B D. None

14. The characteristic impedance Zo of infinite transmission line[ ]

A. C / LB. √LC C. √L/C2D. √L/C

15. _____tells us the ratio of voltage to current at anyone point in an infinitely long line.[ ]

A. Reflection coefficient B. Propagation constant C. Characteristic impedance D. None

16. ______quantifies the line's attenuation properties. [ ]

A. Reflection coefficient B. Propagation constant C. Characteristic impedance D. None

17. Propagation constant y=[ ]

A. √Z/Y B. √Z-Y C. √Z+Y D. √ZY

18. The point Γ= - I in Schmitt chart corresponds to ____ resistance (or reactance). [ ]

A. Infinite B. Minimum C. Maximum D. Zero

19. The point Γ = I in Schmitt chart corresponds to resistance (or reactance. [ ]

A. Infinite B. Minimum C. Maximum D. Zero

20. Most of RF instruments and coaxial cables have standardized impedances of either __ohms[ ]

A. 75 or 100 B. 10 or 40 C. 50 or 75 D. 100 or 75

21. Propagation constant γ =[ ]

A. α-jβ B. α+jβ C. α/jβ D. α2+jβ

22. Since the attenuation is ______at all frequencies, a lossless line has no bandwidth limit.[ ]

A. Infinite B. Minimum C. Maximum D. Zero

23. If the load impedance equals the characteristic impedance of the line, Γ=[ ]

A. Infinite B. Minimum C. Maximum D. Zero

24. At lower frequencies ___ is a powerful intuitive aid in the design of high-BW amplifiers. [ ]

A. OCTs B.SCTs C. Both A and b D. None

25. A technique that satisfied requirement of large band width at low cost is known as ___[ ]

A. Shunt peaking B. Series Peaking C. Both A and B D. None

26. The method of open-circuit time constants OCTS is also known as ____time constants. [ ]

A. Infinite value B. "zero value" C. Both A and B D. None

27. _____ identifies which elements are responsible for bandwidth limitation. [ ]

A. SCTs B. OCTs C. Both A and B D. None

28. _____ is only the model that appropriate to high-frequency regime.[ ]

A. SCTs B. OCTs C. Both A and B D. None

29. _____ is only the model that appropriate to low-frequency regime.[ ]

A. SCTs B. OCTs C. Both A and B D. None

30. SCTS are concerned only with those______that limit low-frequency gain. [ ]

A. Capacitors B. Inductors C. Resistors D. All

31. Overall delay of a cascade of systems is simply the ____ of the individual delays. [ ]

A. Sum B. Product C. Difference D. None

32. First moment of the impulse response defines the____ [ ]

A. Risetime B. Time Delay C. Bandwidth D. None

33. Second moment of the impulse response defines the____ [ ]

A. Risetime B. Time Delay C. Bandwidth D.None

34. Addition rule may be used to ______the limits of instrumentation. [ ]

A. Extend B. Decrease C. Stable D. None

35. trise=______[ ]

A. RC B. 1.1 RC C. 10 RC D. 2.2 RC

36. _____ can be used to enhance the bandwidth [ ]

A. Zeroes B. Poles C. Both A and B D. None

37. An alternative approach to design broadband amplifiers is to use ______feedback[ ]

A. Positive feedback B. Negative C. Both A and B D. None

38. Shunt peaking uses ______network [ ]

A. One-port B. Two-port C. Both A and B D. None

39. Shunt-series amplifier can be used to achieve ______bandwidth [ ]

A. Zero B. Narrow C. Broader D.None

40. Smith chart can be used for matching ______impedances [ ]

A. Load B. Source C. Both A and B D. Zero