Frequently Asked Questions On Antenna Theory With Answers -10.


This page contains basic questions and short notes on some of the keywords on antenna theory:


46) What is a binomial array?

It is an array in which the amplitudes of the antenna elements in the array are arranged according to the coefficients of the binomial series.


47) What are the advantages of binomial array?

Advantage:
  • No minor lobes.

Disadvantages:
  • Increased beam width.
  • Maintaining the large ratio of current amplitude in large arrays is difficult.



48) What is the difference between isotropic and non-isotropic source?
  • Isotropic source radiates energy in all directions but non-isotropic source radiates energy only in some desired directions.
  • Isotropic source is not physically realizable but non-isotropic source is physically realizable.


49) Define Side Lobe Ratio?

Side Lobe Ratio is defined as the ratio of power density in the principal or main lobe to the power
density of the longest minor lobe.


50) List the arrays used for array tapering?

  • Binomial Array:Tapering follows the coefficient of binomial series.
  • Dolph Tchebycheff Array: Tapering follows the coefficient of Tchebycheff polynomial.



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