Question

A sinusoidal carrier wave has an amplitude of 5 volts, a frequency of 1MHz, and zero phase angle. Select the correct carrier wave equation.

		a. c(t) = 1E6 cos(2π*5*t)
		b. c(t) = 5 cos(2π*1E6*t)
		c. c(t) = 5 cos(π*2E6*t)
		d. either b or c

Given the following parameters, select the correct equation for the amplitude modulated (AM) carrier signal. A_m=2.5v, A_c=3v, f_m=3500Hz, f_c=120kHz, φ_m=0, φ_c=0

		a. s(t) = 7[1+1.08 cos(2π3500t)] cos(2π100E3t)
		b. s(t) = 2.5[1+0.83 cos(2π3500t)] cos(2π100E3t)
		c. s(t) = 3[1+2.5 cos(2π3500t)] cos(2π120t)
		d. s(t) = 3[1+0.83 cos(2π3.5E3t)] cos(2π120E3t)

Given the following AM modulated signal, determine the original message, m(t):

s(t) = 2.5[1+0.5 cos(2π25kHzt)] cos(2π88MHzt)

		a. m(t) = 1.25cos(2π25kHz*t)
		b. m(t) = 1.25cos(2π88MHz*t)
		c. m(t) = 2.5cos(2π25kHz*t)
		d. m(t) = 2.5cos(2π88MHz*t)

Given the following message, m(t), carrier, c(t), and Kvco=4300(Hz/v), determine the FM modulated signal equation and FM index. m(t)=2.5cos(2π4000t), c(t)=3cos(2π2GHz*t).

		a. s(t)=2cos(2π5E6t + 1.56sin(2π3500t)), β=1.56
		b. s(t)=3cos(2π2E9t + 2.68sin(2π4E3t)), β=2.68
		c. s(t)=4cos(2π5E9t + 2.57sin(2π3500t)), β=2
		d. s(t)=4cos(2π3500t + 2.57sin(2π5MHz*t)), β=2.57

Given the following FM modulated signal equation, determine the original message equation, m(t).

s(t)= 1.8cos(2π2.4GHz*t + 3sin(2π22kHz*t)), Kvco=4500 (Hz/v)

		a. m(t)= 1.8cos(2π2.4E9t)
		b. m(t)= 1.8cos(2π22E3t)
		c. m(t)= 14.7cos(2π22kHz*t)
		d. m(t)= 3cos(2π13E3t)

Answer 1