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Dr. Mahmoud. A. Abdalla Electronics and Communication Department
EC750 Course Assignment 1/2 Fall 2013
Assignment #1 (Array Antennas)
(Should be submitted by 5th week) Part (1): Uniform Array 1) 4.1 Use Eq. (4.14) and MATLAB and plot the array factor in rectangular
coordinate form for the following broadside array cases
(a) N = 4, d = /2 (b) N = 8, d = /2 (c) N = 8, d = 2) 4.2 For the three arrays given in Prob. 4.1, calculate null and s for each of
the arrays given above.
3) 4.4 Use MATLAB and the command trapz( ) to calculate the maximum directivity for the following two arrays:
(a) Broadside with N = 8, d = /2 (b) End-fire with N = 8, d = /2 4) 4.5 Use MATLAB and the command trapz( ) to calculate the maximum
directivity for the beamsteered array where d = /2, N = 8.
(a) 0 = 30 (b) 0 = 45 5) 4.6 What is the beamwidth for the following array parameters? (a) 0 = 0, N = 8, d = /2 (b) 0 = 45, N = 8, d = /2 (c) 0 = 90, N = 8, d = /2 Part (2): Non Uniform Array 6) 4.7 For an N = 6, d = /2 uniformly weighted broadside array, plot the array
factor. Superimpose plots of the same array with the following weights.
(Create one new plot for each new set of weights) (a) Kaiser-Bessel for = 2 using kaiser(N, ) (b) Blackman-Harris using blackmanharris(N) (c) Nuttall using nuttallwin(N) (d) Chebyshev window for R = 30 dB using chebwin(N, R)
Dr. Mahmoud. A. Abdalla Electronics and Communication Department
EC750 Course Assignment 2/2 Fall 2013
7) 4.10 Using MATLAB, create and superimpose three normalized array factor plots using the chebwin( ) function for R = 40 and beamsteer the array to three angles such that 0 = 0, 30, 60. N = 9, d = /2.
8) 4.12 For d = /2, use MATLAB and plot the N = 8 element array beamwidth for a range of steering angles such that 0 < 0 < 90.
Part (3): Planar Uniform Array 9) 4.15 Design and plot a 5 5 element array with equal element spacing such
that dx = dy = .5. Let the array be beamsteered to 0 = 45 and 0 = 90. The element weights are chosen to be the Blackman-Harris weights using the blackmanharris( ) command in MATLAB. Plot the pattern for the range 0 pi/2 and 0 2pi.
Part (4): Fixed Beam Array 10) 4.16 Using Buttler matrix (Eq (4.56)), create scalloped beams for the N =
6-element array with d = /2.
(a) What are the l values? (b) What are the angles of the scalloped beams? (c) Plot and superimpose all beams on a polar plot similar to Fig. 4.29
11) For the shown 4x4 Butler matrix with 3 dB / +90 coupler, find the magnitudes of the excitation angles
of the four elements array antenna
and their crosssponding maximum
angles, assuming the distance
separation between elements is
d=/2.
12) 4.17 For the fixed beam sidelobe canceller with N = 3-antenna elements, calculate the array weights to receive the desired signal at D = 30, and to
suppress the interfering signals arriving at 1 = 30 and 2 = 60.