Antenna Theory FAQ's

An antenna is a circuit element that provides a transition form a guided wave on a transmission line to a free space wave and it provides for the collection of electromagnetic energy.

In two-way communication, the same antenna can be used for transmission and reception.

In transmit systems the RF signal is generated, amplified, modulated and applied to the antenna. In receive systems the antenna collects electromagnetic waves that are cutting through the antenna and induce alternating currents that are used by the receiver.

Following are the links which will throw more light on the important keywords related to antenna theory:

Antenna Theory - Effective Aperture & Directivity Of A Short Dipole Antenna.

Antenna Theory - What is Polarization & What Are It's Different Types?

1) Define an antenna?

2) What is meant by radiation pattern?

3) Define Radiation intensity?

4) Define Beam efficiency?

5) Define Directivity?


6) What are the different types of aperture?

7) Define different types of aperture?

8) Define Aperture efficiency?

9) What is meant by effective height?

10) What are the field zones?


11) What is meant by Polarization?

12) What is meant by front to back ratio?

13) Define antenna efficiency?

14) What is radiation resistance ?

15) What is meant by antenna beam width?


16) What is meant by reciprocity Theorem?

17) What is meant by isotropic radiator?

18) Define gain?

19) Define self impedance?

20) Define mutual impedance?


21) What is meant by cross field?

22) Define axial ratio?

23) What is meant by Beam Area?

24) What is duality of antenna?

25) State Poynting theorem?


26) What is point source?

27) What is meant by array?

28) What is meant by uniform linear array?

29) What are the types of array?

30) What is Broad side array?


31) Define End fire array?

32) What is collinear array?

33) What is Parasitic array?

34) What is the condition on phase for the end fire array with increased directivity?

35) Define array factor?


36) Define beam width of major lobe?

37) List out the expression of beam width for broad side array and end fire array?

38) Differentiate broad side and End fire array?

39) What is the need for the Binomial array?

40) Define power pattern?


41) What is meant by similar Point sources?

42) What is meant by identical Point sources?

43) What is the principle of the pattern multiplication?

44) What is the advantage of pattern multiplication?

45) What is tapering of arrays?


46) What is a binomial array?

47) What are the advantages of binomial array?

48) What is the difference between isotropic and non-isotropic source?

49) Define Side Lobe Ratio?

50) List the arrays used for array tapering?


Introduction To Short Dipole & How Radiation Are Created From It?



51) What do you understand by retarded current?

52)Define induction field?

53) Define Radiation field?

54) At what distance from the dipole is the induction field equal to the radiation field?

55) Define Radiation Resistance?


56) Give the expression for the effective aperture of a short dipole?

57) What is a dipole antenna?

58) What is a half wave dipole?

59) Give the expression for the effective aperture of a Half wave Dipole?

60) What is the radiation resistance of a half wave dipole?


61) What is a loop antenna?

62) Give an expression of radiation resistance of a small loop?

63) How to increase the radiation resistance of a loop antenna?

64) What are the types of loop antennas?

65) What are Electrically Small loop antennas?


66) What are Electrically large loop antennas?

67) List out the uses of loop antenna?

68) What are the parameters to be considered for the design of an helical antenna?

69) What are the types of radiation modes of operation for an helical antenna?

70) Which antenna will produce circularly polarized waves?

SPACE WAVE PROPAGATION.


71) List the applications of helical antenna?

72) Define Sky wave?

73) Define Tropospheric wave?

74) Define Ground wave?

75) What are the type of Ground wave?


76) What is meant by Space Wave?

77) What is meant by Surface Wave?

78) What is meant by fading?

79) What are the type of fading?

80) What is inverse and multi path fading?


81) What is meant by diversity reception?

82) Define Space diversity Reception?

83) Define frequency diversity Reception?

84) Define polarization diversity reception?

85) What is meant by Faraday's rotation?


86) What are the factors that affect the propagation of radio waves?

87) Define gyro frequency?

88) Define critical frequency?

89) Define Magneto-Ions Splitting?

90) Define LUHF?


91) Define Refractive index?

92)Define maximum Usable Frequency?

93) Define skip distance?

94) Define Optimum frequency?

95) What is wave impedance?

What is Antenna Aperture & What Are It's Types?


ANTENNAS


96) What is Antenna matching?

97) What is a Short Dipole?

98) How are fields created from short dipole / oscillating dipole?

99) What are Antenna Field Zones?

100) What is self impedance and mutual impedance?







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