WorksheetsAntenna Arrays
Total questions: 12
Worksheet time: 6mins
An antenna array (or array antenna) is a set of multiple connected antennas which work together as a _________ antenna, to transmit or receive radio waves.
Directivity increases
Directivity decreases
Beam width decreases
Gain increases
Which of the following statement is true?
As the number of elements increase in array it becomes less directive
As the number of elements increase in array it becomes more directive
Point to point communication is not possible with more number of array element.
There is no uniform progressive phase shift in linear uniform array
An antenna array (or array antenna) is a set of multiple connected antennas which work together as a _________ antenna, to transmit or receive radio waves.
Different
Single
Independent
None
Electrical size of antenna is increased by which of the following?
Antenna Array
Decreasing the coverage area
Increasing the coverage area
Using a single antenna
For long distance communication, which of the property is mainly necessary for the antenna?
High directivity
Low directivity
Low gain
Broad beam width
A uniform linear array contains _____________
N elements placed at equidistance and fed currents of equal magnitude and progressive phase shift
N elements at non-equidistance and fed currents of equal magnitude and progressive phase shift
N elements at equidistance and fed currents of unequal magnitude and progressive phase shift
N elements at equidistance and fed currents of unequal magnitude and equal phase shift
What is the progressive phase shift of the end-fire array?
0
90
180
270
The radiating pattern of single element multiplied by the array factor simply gives the ___________.
Pattern multiplication
Normalized array factor
Beamwidth of the array
Field strength of the array
In Broadside array the maximum radiation is directed with respected to the array axis at an angle____
0
45
90
180
Which of the following statements is false regarding a broadside array?
The maximum radiation is normal to the axis of the array
Must have same amplitude excitation but different phase excitation among different elements
The spacing between elements must not equal to the integral multiples of λ
The phase excitation difference must be equal to zero
Which of the following cannot be the separation between elements in a broadside array to avoid grating lobes?
4λ/2
λ/2
3λ/2
5λ/2
What is the phase excitation difference for an end-fire array?
π
0
±kd/2
±kd
