P-3.1 A signal x(t) has the two-sided spectrum representation shown in Fig. P-3.1 (see below). (a) Write an equation for x(t) as a sum of cosines.

A cable contains 144 single-mode fibers, each operating at 2.3 Gb/s. How many digitized voice messages can be transmitted simultaneously along this cable?

9 An amplifier has a standard noise figure of 2.0. When used with a source,Fop = 2.75. What is the effective noise temperature of the source?

A cascade of three broadband networks with available power gains of 1.8, 6.9,and 6.1 is created. A resistive noise source at temperature T290 K feeds the cascade. What is the available noise power density dN/df at the cascade'soutput?=

A particular radar receiver has a noise figure of 2.1 dB when operating from anantenna with an effective noise temperature Ta = 180 K. What is the standardnoise figure of the receiver?

Give the answers in both Cartesian form (x + jy) and polar form (reje).

8 Work Problem 4.4-6 except for a noise figure and noise temperature of 3.5 dB and 80 K, respectively.