SBM COLLEGE OF ENGINEERING AND TECHNOLOGYDEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERINGUNIT-IV-PASSIVE FILTERSSUB CODE/SUB:EC6503/TLW YEAR/SEM:III/VPART-A 1. Define propagation constant.(MJ-2014)(MJ-2013)(ND-2012)Propagation constant is defined as the natural logarithmic of ratio of input current or voltage to the output current or voltage.

-attenuation constant, -phase constant

2. Write the relationship between neper and decibel.(MJ-2012)Neper=8.686 dBDecibel=0.115 nepers.

3. What is the significance of propagation constant in symmetrical network?(ND-2011)The current ratio or voltage ratio is expressed in exponential term under the condition of ZO termination

Where is a complex number defined as =+j. is the propagation constant. is the attenuation constant. is the phase constant.

4. For a symmetrical network define characteristic impedance.(AM-2011)(MJ-2006)The characteristic impedance is defined as the impedance calculated at the input when the output of a transmission line is terminated by ZO.

5. What are called cutoff frequencies in the design of filters?(MJ-2007)The frequency at which the network changes from a pass band to stop band is called cutoff frequency.Band of frequencies for which the curves lie on opposite side of frequency axis is pass band while the band of frequencies for which the curves lie on same side of frequency axis is stop band. The change over point gives cut-off frequency. So the frequency at which ZO changes from real to imaginary is called cut-off frequency.

6. If ZOC=1000 and ZSC=360, determine the ZO of the symmetrical network.(ND-2009)

7. What are the advantages of m-derived filters.(MJ-2014) (ND-2013) (MJ-2013) (AM-2011) Attenuation rises near cutoff frequency fc and its slope is adjustable by varying f. The characteristic impedance will be uniform in the pass band when m-derived half section having m=0.6 is connected at the ends.

8. State the significance of crystal filters in communication system.(ND-2012) Crystal filter is made up of Piezo electric crystal with high Q factor It act as a narrow band filter. It gives maximum output at resonance and minimum at anti resonance.

9. Write the disadvantages of constant K filter.(MJ-2012)(MJ-2009) Attenuation does not increase rapidly beyond the cutoff frequencies. Characteristic impedance varies widely in the pass band from its desired value Rk.

10. Draw the equivalent electrical circuit for piezoelectric crystal filter.(ND-2011)11. Draw a simple HPF section and give the values of circuit elements.(ND-2007)12. Draw a simple BPF section and give the values of circuit elements.(ND-2007)13. Define constant K filters.(MJ-2007)(MJ-2006)In symmetrical network, Z1 is series impedance and Z2 is shunt impedance.Then Z1Z2=k2 where k is a constant independent of frequency. This network is called as constant k filter.

14. What are the properties of band elimination filters?(MJ-2007) A band elimination filter is a network which attenuates frequencies between two cutoff frequencies f1 and f2 and passes all other frequencies. It can be thought of as a LPF in parallel with high pass section, in which the cutoff frequency of the LPF is below that of HPF. The series arm and the shunt arm are made anti-resonant (parallel resonance) and resonant at the same frequency fO.

15. How the resonant frequency is chosen in the m-derived high pass filter?.(MJ-2007)Shunt arm is a series circuit resonant at frequency f above fC. A t this resonant frequency the shunt appears as a short circuit on the network, or the attenuation becomes infinite. This frequency of infinite or high attenuation is called f.

16. Determine the value of L required by a constant K T section high pass filter with cutoff frequency of 1.5 KHz and design impedance of 500.(MJ-2014)

17. Determine the value of C required by a constant K-T LPF with cutoff frequency of 2 KHz and design impedance of 500.(MJ-2014)

18. Determine the value of L required by a constant K T section high pass filter with cutoff frequency of 10 KHz and design impedance of 600. (MJ-2013)(ND-2010)

19. Determine the value of C required by a constant K-T LPF with cutoff frequency of 1.5 KHz and design impedance of 600.(MJ-2013)

20. Find L and C of LPF having cutoff frequency of 1.8 KHz and load of 500.(MJ-2009)

21. Determine the value of C required by a constant K-T HPF with cutoff frequency of 1 KHz and design impedance of 600.(AM-2008)

Sixteen mark questions 1. Derive the expression for characteristic impedance of symmetrical T and section networks.(MJ-2013)(ND-2011)The characteristic impedance is defined as the impedance measured at the input when the network is terminated with ZO.T- network(i)ZO in terms of series and shunt arm impedance

(ii) ZO in terms of open and short circuits

- network(i) ZO in terms of series and shunt arms

(ii) ZO in terms of open and short circuits

2. Bring out the relation between Decibel and Neper.(MJ-2013) Let

3. Explain the properties of symmetrical networks.(ND-2012)(ND-2011)(ND-2009)(i) Propagation constant of a network terminated with load ZO.

(ii) Input impedance of network terminated with ZR.

4. With suitable filter sections, design constant low pass and high pass filters.(ND-2011)Constant K Low Pass Filter

A pass band starts at f=0 and continues to some higher frequency fC is called cutoff frequency. All frequencies above fC lie in a stop or attenuation band, thus the network is called low pass filter.At the cutoff frequency fC point

Constant K High pass Filter

Pass band starts at a cutoff frequency fC at Z1= -4Z2 to infinity where Z1=0. The network is a high pass filter. All the frequencies below the fC is stop band.

5. Draw and explain the design and operation of constant K-T section band pass filter with necessary equations and diagrams.(AM-2008) It is a network which passes a band of frequencies and attenuates frequencies on both sides of the pass band. The BPF can be achieved by cascading of LPF and HPF in series.The series resonant frequency and shunt resonant frequency are same.

Design

6. Draw and explain the design and operation of constant K-T section band elimination filter with necessary equations and diagrams.(MJ-2014)(ND-2013)(MJ-2013)(MJ-2012)(ND-2010)The series and parallel arms of Band Pass Filter are interchanged. At the cutoff frequencies Z1=-4 Z2 Z1Z2=-4

7. Design and derive m-derived LPF with relevant diagrams.(ND-2007)T sec LPF : m derived filters can be obtained from constant K prototype filter by modifying the shunt impedance and multiplying the series impedance by m, while keeping constant characteristic impedance ZO. Z1=2fL and Z2=

and

8. Draw and explain the design and operation of m-derived T section band pass filter with necessary equations and diagrams.(MJ-2014)(MJ-2013)At f, the impedance of the series resonant circuit and parallel resonant circuit of the shunt arm will be equal and opposite type. ,

, ,

9. Design constant K band pass filters (both T & sections) for the cutoff frequencies of 12 KHz & 16 KHz. The design impedance is 600 .(MJ-2014)

10. Design a constant K band pass filter (both T & sec)having a design impedance of 600 and cutoff frequencies of 1KHz and 4KHz.(ND-2013)(ND-2010)

11. Design constant K band elimination filters (both T & sections) for the cutoff frequencies of 3KHz & 7KHz. The design impedance is 500 .(MJ-2013)

12. Design T and section LPF which has series inductance 80mH and shunt capacitance 0.022F. find the cutoff frequency and design impedance.(ND-2012)

13. Calculate the values of the inductor and capacitors of a prototype constant K LPF composed of section to operate with a terminating load of 600 and to have a cutoff frequency of 3KHz.(MJ-2012)63.66 mH0.176F

14. Design LPF (T & ) having cutoff frequency of 2 KHz to operate with a terminated load resistance of 500.(MJ-2006)79.5 mH0.318F

15. Design HPF having cutoff frequency of 1 KHz with a load resistance 600.(MJ-2006)47.7 mH0.133F 2C=0.266F 2L=95.4 mH

16. Design an m-derived low pass filter with cutoff frequency of 2 KHz. Design impedance is 500 and m=0.4. Consider a section.(MJ-2014)

17. Design an m-derived High pass filter with cutoff frequency of 10 KHz. Design impedance is 600 and m=0.6. Consider a T section.(MJ-2014)

18. Design an m-derived T section LPF having cutoff frequency of 1KHz. Design impedance is 400 and the resonant frequency is 1100Hz.(ND-2013)

19. Design an m-derived High pass filter with cutoff frequency of 4KHz. Design impedance is 600 and m=0.4. Consider a section.(MJ-2014)

20. Design an m-derived T section LPF having cutoff frequency fc=1000Hz, design impedance RK=600 and frequency of infinite attenuation f=1050Hz.(MJ-2012)

21. Design m-derived T type LPF to work into load of 500 with cutoff frequency at 4KHz and peak attenuation at 4.15 KHz.(AM-2011)

22. Design LPF with cutoff at 2600 Hz to match 550. Use one derived section with infinite attenuation at 2850 Hz.(AM-2011)

23. Design m-derived T section LPF having fc=5000Hz and a design impedance of 600. The frequency of infinite attenuation is 1.25fc.(ND-2010)

24. Design m derived HPF(T & ) having design resistance RO=500, cutoff frequency fc=10KHz and m=0.4.(AM-2008)

QUESTION BANKPART-A1. Define propagation constant.(MJ-2014)(MJ-2013)(ND-2012)2. Write the relationship between neper and decibel.(MJ-2012)3. What is the significance of propagation constant in symmetrical network?(ND-2011)4. For a symmetrical network define characteristic impedance.(AM-2011)(MJ-2006)5. What are called cutoff frequencies in the design of filters?(MJ-2007)6. If ZOC=1000 and ZSC=360, determine the ZO of the symmetrical network.(ND-2009)7. What are the advantages of m-derived filters. (MJ-2014)(ND-2013)(MJ-2013)(AM-2011)(ND-2010)(ND-2009)8. State the significance of crystal filters in communication system.(ND-2012) 9. Write the disadvantages of constant K filter.(MJ-2012)(MJ-2009)10. Draw the equivalent electrical circuit for piezoelectric crystal filter.(ND-2011)11. Compare constant K and m-derived filters.(AM-2008)12. Draw a simple HPF section and give the values of circuit elements.(ND-2007)13. Draw a simple BPF section and give the values of circuit elements.(ND-2007)14. Define constant K filters.(MJ-2007)(MJ-2006)15. What are the properties of band elimination filters?(MJ-2007)16. How the resonant frequency is chosen in the m-derived high pass filter?.(MJ-2007)

PROBLEMS17. Determine the value of L required by a constant K T section high pass filter with cutoff frequency of 1.5 KHz and design impedance of 500.(MJ-2014)18. Determine the value of C required by a constant K-T LPF with cutoff frequency of 2 KHz and design impedance of 500.(MJ-2014)19. Determine the value of L required by a constant K T section high pass filter with cutoff frequency of 1 KHz and design impedance of 600.(ND-2013)20. A constant K-T section high pass filter has a cutoff frequency of 10 KHz. The design impedance is 600. Determine the value of L.(MJ-2013)(ND-2010)21. Determine the value of C required by a constant K-T LPF with cutoff frequency of 1.5 KHz and design impedance of 600.(MJ-2013)22. Find L and C of LPF having cutoff frequency of 1.8 KHz and load of 500.(MJ-2009)23. Determine the value of C required by a constant K-T HPF with cutoff frequency of 1 KHz and design impedance of 600.(AM-2008)PART-B1. Derive the expression for characteristic impedance of symmetrical T and section networks.(MJ-2013)(ND-2011)2. Bring out the relation between Decibel and Neper.(MJ-2013)3. Explain the characteristic impedance and propagation constant of symmetrical networks with necessary equations and diagrams.(MJ-2013)(MJ-2012)4. Explain the properties and characteristic impedance of symmetrical networks.(ND-2012)(ND-2011)(ND-2009)5. Draw and explain the design and operation of m-derived T section band pass filter with necessary equations and diagrams.(MJ-2014)(MJ-2013)6. Explain the principle and operation of crystal filters with neat diagrams. Discuss the advantages and applications.(MJ-2014)(ND-2013)(MJ-2013)(ND-2010)7. Draw and explain the design and operation of constant K-T section band elimination filter with necessary equations and diagrams.(MJ-2014)(ND-2013)(MJ-2013)(MJ-2012)(ND-2010)8. Draw and explain the design and operation of constant K-T section band pass filter with necessary equations and diagrams.(AM-2008)9. Design and derive m-derived LPF with relevant diagrams.(ND-2007)10. With suitable filter sections, design constant low pass and high pass filters.(ND-2011)

PROBLEMS- constant K filters11. Design constant K band pass filters (both T & sections) for the cutoff frequencies of 2 KHz & 6 KHz. The design impedance is 500 .(MJ-2014)12. Design constant K band pass filters (both T & sections) for the cutoff frequencies of 12 KHz & 16 KHz. The design impedance is 600 .(MJ-2014)13. Design a constant K band pass filter (both T & sec)having a design impedance of 600 and cutoff frequencies of 1KHz and 4KHz.(ND-2013)(ND-2010)14. Design constant K band elimination filters (both T & sections) for the cutoff frequencies of 3KHz & 7KHz. The design impedance is 500 .(MJ-2013)15. Design T and section LPF which has series inductance 80mH and shunt capacitance 0.022F. find the cutoff frequency and design impedance.(ND-2012)16. Calculate the values of the inductor and capacitors of a prototype constant K LPF composed of section to operate with a terminating load of 600 and to have a cutoff frequency of 3KHz.(MJ-2012)17. Design LPF (T & ) having cutoff frequency of 2 KHz to operate with a terminated load resistance of 500.(MJ-2006)18. Design HPF having cutoff frequency of 1 KHz with a load resistance 600.(MJ-2006)

PROBLEMS- m-derived filters19. Design an m-derived low pass filter with cutoff frequency of 2 KHz. Design impedance is 500 and m=0.4. Consider a section.(MJ-2014)20. Design an m-derived High pass filter with cutoff frequency of 10 KHz. Design impedance is 600 and m=0.6. Consider a T section.(MJ-2014)21. Design an m-derived T section LPF having cutoff frequency of 1KHz. Design impedance is 400 and the resonant frequency is 1100Hz.(ND-2013)22. Design an m-derived High pass filter with cutoff frequency of 4KHz. Design impedance is 600 and m=0.4. Consider a section.(MJ-2014)23. Design m derived LPF(T & ) having design resistance RO=500, cutoff frequency fc=1500Hz and infinite attenuation frequency f=1KHz.(ND-2012)24. Design an m-derived T section LPF having cutoff frequency fc=1000Hz, design impedance RK=600 and frequency of infinite attenuation f=1050Hz.(MJ-2012)25. Design m-derived T type LPF to work into load of 500 with cutoff frequency at 4KHz and peak attenuation at 4.15 KHz.(AM-2011)26. Design LPF with cutoff at 2600 Hz to match 550. Use one derived section with infinite attenuation at 2850 Hz.(AM-2011)27. Design m-derived T section LPF having fc=5000Hz and a design impedance of 600. The frequency of infinite attenuation is 1.25fc.(ND-2010)28. Design m derived HPF(T & ) having design resistance RO=500, cutoff frequency fc=10KHz and m=0.4.(AM-2008)29. Design m-derived LPF having cutoff frequency of 1 KHz, design impedance of 400 and the resonant frequency of 1100Hz.(MJ-2006)30. Design m-derived HPF with a cutoff frequency of 10 KHz, design impedance 5 and m=0.4.(MJ-2006)

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