STRLCPY/wirelesscomm

--Changed m to mlx files --Updated the course admin
Sundeep Rangan committed 2 years ago

9999a1bf

1 parent 7d38d416

lectures/CourseAdmin.pdf

Binary file.
lectures/CourseAdmin.pptx

Binary file.
unit01_antennas/lab_uav_antenna.mlx

Binary file.
unit01_antennas/lab_uav_antenna.pdf

Binary file.

■ ■ ■ ■ ■ ■

unit01_antennas/lab_uav_antenna_partial.m

1	-	%% Simulating a 28 GHz antenna for a UAV
2	-	%
3	-	% For complex antennas, it is often necessary to perform detailed EM
4	-	% simulations in third-party software such as HFSS and then import
5	-	% the results into MATLAB for analysis. In this lab, we will import HFSS
6	-	% simulation data for a 28 GHz antenna designed for a UAV (unmanned aerial
7	-	% vehicle or drone). Antenna modeling is particularly important for mmWave
8	-	% aerial links since the directivity gain is necessary to overcome the
9	-	% high isotropic path loss of mmWave frequencies. Also, UAVs can be
10	-	% an arbitrary orientation and it is important to model the cases when
11	-	% the UAV is out of the beamwidth of the antenna.
12	-	%
13	-	% In going through this lab, you will learn to:
14	-	%
15	-	% * Import data from an EM simulation data given as a
16	-	% <https://www.mathworks.com/help/matlab/ref/table.html MATLAB table object>.
17	-	% * Compute directivity from E-field values
18	-	% * Create custom arrays in MATLAB's phased array toolbox
19	-	% * Display 2D and 3D antenna patterns
20	-	% * Compute the half-power beamwidth (HPBW) of an antenna
21	-	% * Compute fractions of power in angular areas
22	-	% * Estimate the path loss along a path
23	-	%
24	-	% Submission: Complete all the sections marked \|TODO\|, and run the cells
25	-	% to make sure your scipt is working. When you are satisfied with the
26	-	% results, <https://www.mathworks.com/help/matlab/matlab_prog/publishing-matlab-code.html
27	-	% publish your code> to generate an html file. Print the html file to
28	-	% PDF and submit the PDF.
29	-
30	-
31	-	%% Load the data
32	-	% The data for this lab was generously donated by Vasilii
33	-	% Semkin of VTT and taken from the paper:
34	-	%
35	-	% * W Xia,V. Semkin, M. Mezzavilla, G. Loianno, S. Rangan,
36	-	% Multi-array Designs for MmWave and Sub-THzCommunication to UAVs,
37	-	% 2020
38	-	%
39	-	% The paper performs EM simulations on a ciccularly polarized
40	-	% 28 GHz antenna mounted to the bottom of a commercial DJI Matrice 100
41	-	% quadrocopter. An image of the drone with the antenna and its pattern
42	-	% is shown in the following picture.
43	-	A = imread('CP_patch_downwards_m100_3D_coord.png');
44	-	imshow(A, 'InitialMagnification', 40);
45	-
46	-	%%
47	-	% We will first load the data with the following command.
48	-	load patch_bottom_data.mat
49	-
50	-	%%
51	-	% Running the above command should create an object, \|data_table\|, in
52	-	% your workspace. The \|data_table\| object is a MATLAB table,
53	-	% which is like a SQL table. Run the following command to see the first
54	-	% five rows. You should see the fields in each table entry including
55	-	% the azimuth and elevation and the corresponding V and H fields.
56	-	data_table(1:5,:)
57	-
58	-	%% Reading and the data table
59	-	% We can read the table columns into MATLAB arrays with commands such as,
60	-	%
61	-	% col = data_table(:,{column_name}).Variables;
62	-
63	-	% TODO: Read the 'Elevation' and 'Azimuth' columns into matlab arrays
64	-	% el and az.
65	-
66	-
67	-	%%
68	-	% In this simulation, the antenna was pointed upwards, meaning that the
69	-	% boresight is at an elevation of 90 degrees. But, since we want to
70	-	% simulate antenna pointing downwards, we need to switch the signs of the
71	-	% elevation angles.
72	-
73	-	% TODO: Switch the elevation angles with el = -el;
74	-
75	-	%% Getting the E-field
76	-	% Most EM simulations prodcuce outputs as E-field at some distance from the
77	-	% antenna. The E-field is represented by two complex values, one for
78	-	% the H polarization and for the V polarization.
79	-
80	-	% TODO: Read the complex E-fields from the data_table object. Store them
81	-	% in variables EH and EV.
82	-
83	-
84	-	%%
85	-	% Recall that the radiation intensity and any point is proportional to
86	-	% the E-field power,
87	-	%
88	-	% W = Epow/eta, Epow = \|EH\|^2 + \|EV\|^2.
89	-	%
90	-	% where eta is characteristic impedance. This is the power flux
91	-	% that can be received by an antenna exactly aligned in polarization
92	-	% with the E-field.
93	-
94	-	% TODO: Compute the E-field power, Epow = \|EH\|^2 + \|EV\|^2.
95	-	% Remember to use the MATLAB abs() command.
96	-
97	-
98	-	%% Compute the directivity
99	-	% We next compute the directivity of the antenna. The directivity
100	-	% of the antenna is given by,
101	-	%
102	-	% dir = U / Ptot
103	-	%
104	-	% where Ptot is the total radiated power and U is the far-field
105	-	% radiation density
106	-	%
107	-	% U = r^2 W = r^2 Epow / eta
108	-	%
109	-	% Hence, the directivity (in linear scale) is:
110	-	%
111	-	% dir = c*Epow
112	-	%
113	-	% for some constant c. To compute the constant c, we know that
114	-	% the average of the directivity dir * cos(el) over a spherical integral
115	-	% must be one. Hence, if we take mean over the discrete values, you should
116	-	% have that:
117	-	%
118	-	% mean(dir.*cos(el)) / mean(cos(el)) = 1
119	-	%
120	-	% You can use this relation to find the scale factor, c.
121	-	%
122	-	% TODO: Compute a vector, dir, with the directivity of each point
123	-	% in dBi. Remember, MATLAB's cos() function takes the argument in
124	-	% radians.
125	-
126	-
127	-	% TODO: Print the maximum gain.
128	-
129	-	%% Plotting the 3D antenna pattern
130	-	% To plot the antenna pattern, we will create a CustomAntennaObject in
131	-	% MATLAB's phased array toolbox. However, to use the CustomAntennaObject,
132	-	% we need to re-format the directivity vector into a matrix. The process
133	-	% is tedious, but conceptually simple. What we need to do is create
134	-	% a matrix, \|dirMat\|, with values, \|dirMat(i,j)\| is the directivity
135	-	% at (elevation, azimuth) angles \|(elval(i), azval(j))\|.
136	-	elvals = (-90:2:90)';
137	-	azvals = (-180:2:180)';
138	-	nel = length(elvals);
139	-	naz = length(azvals);
140	-
141	-	%%
142	-	% If you have done everything correctly up to now, you will have a vector,
143	-	% dir, that is should be naz*nel x 1. To convert this to the
144	-	% dirMat matrix, you can do the following:
145	-	%
146	-	% * Reshape the vector, \|dir\|, into a directory \|dirMat\| of size
147	-	% \|naz x nel\| Take the transpose of the matrix so it is \|nel x naz\|.
148	-	% * Circularly shift (using the MATLAB command circshift) so that the first
149	-	% column of dirMat is moved to the position corresponding to az=0. We do
150	-	% this since the angles in dirMat go from 0 to 360, not -180 to 180
151	-	% * Flip the dirMat vertically with the MATLAB command flipud. We do this
152	-	% since we want to look at an antenna pattern facing downwards
153	-	%
154	-	% TODO: Create dirMat as above
155	-
156	-
157	-	% TODO: Now, create the antenna object with the correct parameters
158	-	% Use an all zero phasePattern.
159	-	%
160	-	% phasePattern = ...
161	-	% ant = phased.CustomAntennaElement(...)
162	-
163	-
164	-	% TODO: Plot the antenna pattern with the ant.pattern() command
165	-	fc = 28e9;
166	-
167	-
168	-	%% Plot a polar 2D plot
169	-	% We next plot a 2D antenna pattern
170	-	%
171	-	% TODO: Use the ant.patternElevation(...) to plot the antenna cut
172	-	% at azPlot = 0 degrees
173	-	azPlot = 0;
174	-
175	-
176	-	%% Computing the half-power beamwidth
177	-	% The half-power beamwidth is a common value in describing the
178	-	% directivity of an antenna. We show how this quantity can be computed.
179	-	% First, get the numerical values of the directivity along a cut
180	-	% at azPlot = 0. We do this with the same command as above, but with
181	-	% an output argument:
182	-
183	-	% TODO: Run the clf('reset') command. This is needed since the last plot
184	-	% was a pattern plot,
185	-
186	-	% TODO: dircut = ant.patternElevation(...);
187	-
188	-	% This returns the directivity along eleation angles elcut
189	-	elcut = (-180:180);
190	-
191	-	%%
192	-	% The HPBW is the range of angles that correspond to the directivity
193	-	% 3 dB below the peak.
194	-	%
195	-	% TODO: Use the dircut and elcut vectors to find and print the HPBW.
196	-
197	-
198	-	%% Computing power fractions.
199	-	% Often we are interested in finding the fraction of radiated power
200	-	% in some angular region. The fraction of power radiated in any
201	-	% region is proportional to the sum of values Epow(i)*cos(el(i))
202	-	% for all points i in the region.
203	-	%
204	-	% TODO: Use this relation to print the fraction of power radiated in
205	-	% the upper hemisphere. This should be small, since most of the
206	-	% power is radiated downwards.
207	-
208	-
209	-	% TODO: Print the power fraction within the HPBW:
210	-
211	-
212	-
213	-	%% Computing the path loss along a path
214	-	% Following the code in the demo, plot the path loss (omni and
215	-	% with element gain) of a UAV RX flying from (0,0,30) to (500,0,30)
216	-	% in a linear path. Assume the TX is at (0,0,0).
217	-	%
218	-	% TODO: Plot the omni and directional path loss vs. x position.
219	-	%
220	-	% You should see initially that you obtain significant antenna gain
221	-	% since the antenna is facing downwards to the TX. But, as you fly
222	-	% the antenna gain decreases and becomes negative. Before plotting you
223	-	% will want to run the command, clf('reset'). This is necessary since the
224	-	% pattern plots above screw up later figures.
225	-
226	-

unit01_antennas/lab_uav_antenna_partial.pdf

Binary file.

--Changed m to mlx files --Updated the course admin