Am Calculation.docx

AM CALCULATION 1. Modulating signal Vm (t) = Em sin Ꞷmt Ꞷm

=2πfm =2π(10MHz) =62.8319MHz

Vm (t) =6 sin 62.8319M =2.0521 2. Carrier signal Vc (t) = Ec sin Ꞷct Ꞷc

=2πfc =2π(300MHz) =1884.9556MHz

Vc (t) =10 sin 1884.9556M = -9.8481 3.Modulation index M=

Em Ec

M=

6 10

M = 0.6 4. Modulated signal Vam (t)=Ec sin Ꞷct +

mEc 2

= 10 sin 1884.9556M +

cos (Ꞷc − Ꞷm) t +

(0.6)(10) 2

mEc 2

cos (Ꞷc + Ꞷm) t

cos (1884.9556M−62.8319M) +

(0.6)(10)

(1884.9556M+62.8319M) = 10 sin (1884.9556M) + 3 cos (1822.1237M) + 3 cos (19.47.7875M)

2

cos

5. Frequency spectrum fusb = fc + fm = 300M + 10M = 310Mhz flsb = fc − fm = 300M − 10M = 290MHz Elsb = Eusb =

=

mEc 2 (0.6)(0.10) 2

=3 6. Bandwith B = (fc + fm) − (fc − fm) = 2fm = 2(10M) = 20MHz

vDSBSC (𝑡) =

Em Em cos (ωc − ωm)t + cos (ωc + ωm)t 2 2

= 3 cos (1822.1237M) + 3 cos (1947.7875M)

7.Frequency Spectrum 10V

3V

3V

290MHz

300MHz 20MHz

310MHz

FM CALCULATION 1. Carrier signal Vc (t) = Vc cos (ωc t) ωc = 2Π fc ωc = 2Π (100M) = 628.3185M Vc (t) = 10 cos 628.3185M

2. Information signal Vm (t) = Vm cos (ωm 𝑡) ωm = 2πfm ωm = 62.8319kHz Vm (t) = 8 cos 62.8319k

3. Modulation index mf =

𝛥𝑓 𝑓𝑚

mf = 0.5 Δf = mf fm Δf = 5kHz Kf =

Δf Vm

K f = 625Hz/v fcs = 2Δf = 2(5k) = 10kHz Smpai sini je aku buat samiq. Aku nak masuk kan data dkat bawah ni tak sure. Kau tgok mane nak kne betulkan. Nnti pass balik 4. Basel polynomial table M 2.0

J0 0.22

J1 0.58

J2 0.35

Vfm (t) = VC cos (wc t + mf Sin wm t) = 10 cos (1884.9556M)t + 2 sin (62.8319MHz)

J3 0.13

J4 0.03

5. Amplitude of the spectrum Mvc J0 = 2(10)0.22 = 4.4V Mvc J1 = 2(10)0.58 = 11.6V Mvc J2 = 2(10)0.35 = 7V Mvc J3 = 2(10)0.13 = 2.6V Mvc J4 = 2(10)0.03 = 0.6V

6.Frequency component of the spectrum fc = 300MHZ fc + fm = 300M + 10M = 310MHz fc + 2fm = 300M + 20M = 320MHz fc + 3fm = 300M + 30M = 330MHz fc + 4fm = 300M + 40M = 340MHz fc + 5fm = 300M + 50M = 350MHz

fc − fm = 300M − 10M = 290MHz fc − 2fm = 300M − 20M = 280MHz fc − 3fm = 300M − 30M = 270MHz fc − 4fm = 300M − 40M = 260MHz fc − 5fm = 300M − 50M = 250MHz

7.Bandwith of the FM signal Bw = fmax − fmin Bw = 340M − 260M Bw = 80MHz

8.Frequency Spectrum 11.6V

11.6V 10V

7V

7V 4.4V

4.4V 2.6V

2.6V 0.6V

0.6V

250MHzCIRCUIT 260MHzSIMULATION 290MHz DESIGN 270MHz 280MHz

300MHz 80MHz

310MHz

320MHz

330MHz 340MHz

350MHz

AMPLITUDE MODULATION CIRCUIT

FREQUENCY MODULATION CIRCUIT

RESULT AM MODULATION

AMPLITUDE MODULATED SIGNAL

FREQUENCY SPECTRUM OF AMPLITUDE MODULATION

From the result that we get from Matlab, we can see that we get a true amplitude modulation wave as in theory that we had learned in class. Also, we can see that the both of calculation and simulation for spectrum frequency is same. In Matlab, the value show for Fc, Fc+Fm, and Fc-Fm is same as in the calculation that is 300M Hz, 310M Hz and 290M Hz. There are some slight error while doing the simulation so the frequency spectrum that we get is slightly different from the calculation.It is because we use wrong scale value for amplitude. The calculation and simulation is as shown above.

FM MODULATION

FREQUENCY MODULATED SIGNAL

FREQUENCY SPECTRUM OF FREQUENCY MODULATION From the result that we get from Matlab, we can see that we get a true frequency modulation wave as in theory that we had learned in class. Also, we can see that the both of calculation and simulation for spectrum frequency is same. In Matlab, the value show for Fc, Fc+Fm, Fc-Fm, Fm+2Fm, Fc-2Fm and more is same as in the calculation that is 300M Hz, 310M Hz, 290M Hz, 320M HZ and 280M Hz. There are some distortion while doing the simulation so the frequency spectrum that we get is slightly different from the calculation.It is because we use wrong scale value for amplitude. The calculation and simulation is as shown above.