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This set of Antennas Multiple Choice Questions & Answers (MCQs) focuses on “Adaptive Array – Antenna Synthesis”.

1. Antenna synthesis is inverse process to antenna analysis.
a) True
b) False

Explanation: Antenna synthesis determines the distribution of input or output sources from the obtained radiation pattern. Antenna analysis is determining the radiation pattern for the given input distribution.

2. In which of the following methods nulls are introduced in the desired direction of pattern?
a) Schelkunoff
b) Taylor
c) Woodward
d) Fourier

Explanation: In Schelkunoff method, pattern is produced with null in specified directions. Woodward method is suited for beam shaping and Fourier is used when the complete pattern and excitation distributions locations are given. Taylor series have a constant inner minor lobes level and decreasing lobes for other.

3. In which of the following method is popularly used for beam shaping in antenna synthesis?
a) Woodward
b) Schelkunoff
c) Fourier
d) Taylor

Explanation: Woodward method is suited for beam shaping and the complete pattern and excitation distributions locations are given by the Fourier method. The nulls in specified pattern are produced by the Schelkunoff method. The Taylor synthesis has a constant inner minor lobes level.

4. Which of the following synthesis method have a constant inner minor lobe level and remaining one decreasing gradually?
a) Woodward
b) Schelkunoff
c) Fourier
d) Taylor

Explanation: Taylor synthesis has a constant inner minor lobes level and gradually decreasing lobes for other. Nulls are produced in a specified direction for the pattern using Schelkunoff method. The Woodward method is used for beam shaping in antenna synthesis while Fourier is used when the complete pattern and excitation distributions locations are given.

5. Antenna synthesis is analogous to _____
a) Antenna array
b) Antenna analysis
d) Schelkunoff synthesis

Explanation: Schelkunoff is one of the methods of antenna synthesis. Antenna synthesis determines the distribution of input or output sources from the obtained radiation pattern. Antenna analysis is determining the radiation pattern for the given input distribution.

6. Which of the following is not a technique of antenna synthesis?
a) Woodward
b) Schelkunoff
c) Fourier
d) Thinning

Explanation: Thinning is a process to reduce the array elements with degrading the performance. Woodward-Lawson, Schelkunoff, Fourier, Taylor are techniques of antenna synthesis.Antenna synthesis determines the distribution of input or output sources from the obtained radiation pattern.

7. Which of the following method is used for antenna design with no side lobes?
a) Binomial array
b) Dolph Chebyshev
c) Schelkunoff
d) Woodward

Explanation: Dolph Chebyshev is a special case (at no side lobes) of Binomial array. Dolph Chebyshev is used to design array at desired side lobes. In Schelkunoff method, pattern is produced with null in specified directions. Woodward method is suited for beam shaping.