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Elon Musk - Things you do

... If you only do things, that are certain to succeed then you only gonna be doing very obvious things ...

TI-89 - Error: Memory

If you are using TI-89 Titanium calculator and see message "Error: Memory" when trying to solve some equations or integrals that could be you are giving the input sentence wrong - for example missing '*' character between the elements, like:

Instead of using z(10-2)=25 try z*(10-2)=25.

How to set font size in Matlab figure - it is easy

figure(1)
plot(freq, V, 'linewidth', [2])
set(gca,'fontsize',[14])
xlabel('Frequency [GHz]')
ylabel('Voltage [V]')

Keep forgetting this again and again.
Now will have it always available here.

Balanis - Antenna 3rd Edition - Problem 2.11

a) D_o = 4; in dB :: D_o = 6.0206 dB
HPBW(θ) = 120^o, HPBW(φ) = 120^o

b) D_o = 5.093; in dB :: D_o = 7.0697 dB
HPBW(θ) = 120^o, HPBW(φ) = 90^o

c) D_o = 6; in dB :: D_o = 7.7815dB
HPBW(θ) = 120^o, HPBW(φ) = 74.93^o

d) D_o = 4.7124; in dB :: D_o = 6.7324 dB
HPBW(θ) = 90^o, HPBW(φ) = 120^o

e) D_o = 6; in dB :: D_o = 7.7815 dB
HPBW(θ) = 90^o, HPBW(φ) = 90^o

f) D_o = 7.0686; in dB :: D_o = 8.4933 dB
HPBW(θ) = 90^o, HPBW(φ) = 74.93^o

How to calculate Half Power Beamwidth

4 Steps procedure:

        1) Normalize U

        2) Find θ_MAX

        3) Set U = 0.5, solve for θ

        4) Substract 3) from 2) and multiply by 2

Balanis - Antenna 3rd Edition - Problem 2.4

a) HPBW = 2.09 rad

b) HPBW = 1.57 rad

c) HPBW = 1.047 rad

d) HPBW = 0.785 rad

e) HPBW = 0.698 rad

f) HPBW = 0.523 rad