WilliamsA1 - Shadia Williams Patrick Behr Naman Batt 1...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
Shadia Williams Patrick Behr Naman Batt 1 Modulation is a impressing a low frequency intelligence signal onto a higher frequency carrier signal. 2 A carrier frequency is a frequency of the un modulated electrical wave at the output of an amplitude modulated transmitter 3 Without modulation the waves would interfere with each other. It is also impossible to transmit at that low of a frequency. 4 Peak value, angular velocity, and phase angle. 5 300kHz-30Ghz 6 -7.95 dbuV dBuV=20Log^10(V^2/1uV) 7 V=vPR 2.45V 8 3.87 dB=10Log^10(p^2/P^1) 9 30dBm 0dBm -10dBm -16dBm 0dBm=.001W 106.3W, 8dBW 0dBm=.001W 11.245mV 0dBm=.001W 1234dBuV
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Shadia Williams Patrick Behr Naman Batt 0dBm=.001W 138.86dBm dBuV=20Log^10(V^2/1uV) 1419.66dBm dBuV=20Log^10(V^2/1uV) 15. Electrical noise defined as any undesired voltages or currents that ultimately end up appearing in the receiver output. A communications receiver is a very sensitive instrument that is given a very small signal at its input that must be greatly amplified before it can possibly drive a speaker that is why it is so troublesome to a communication receiver. 16. The noise present in a received radio signal that has been introduced in the transmitting medium is termed External Noise. The noise introduced by the receiver is termed Internal Noise. 17. External Noise: Human-Made Noise: It is often produced by spark- producing mechanism such as engine ignition systems, fluorescent lights, and commutators in electric motors. This noise is actually “radiated” or transmitted from its generating sources through the atmosphere in the same fashion that a transmitting antenna radiates desirable electrical signals to a receiving antenna. This process is called wave propagation. Atmospheric Noise: It is caused by naturally occurring disturbances in the earth’s atmosphere, with lighting discharges being the most prominent contributors. Space Noise: It arrives from outer space. It is pretty evenly divided in origin between the sun and all the other stars. That originating from our star (the sun) is termed solar noise. All the other stars also generate this space noise, and their contribution is
Background image of page 2
Shadia Williams Patrick Behr Naman Batt termed cosmic noise. 18. Two other names for Johnson noise: Thermal Noise White Noise e n = v(4kT∆fR) = v(4 x 1.38 x 10 -23 x 300 x 1M x 1M) = 128.7µV 19. Using formula R = = 33.66MΩ (I think book’s answer is wrong.) And using e = v (4kT∆fR) = 120µV (R = 33.66MΩ) 20. Dissimilar resistors of equal values exhibit different noise levels, which gives rise to the
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 13

WilliamsA1 - Shadia Williams Patrick Behr Naman Batt 1...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online