Chapter 7, Problem 7.93IP

12.38 If the circuit shown in Fig. P12.38(a) is excited by the current waveform is(t) shown in Fig. P12.38(b), determine i(t) for 1 > 0, given that R₁ = 102, R2 = 5 92, and C = 0.02 F. is(t) R₁ i(t) R₂ is(t) 1.5 A 1.5A | 1 A 0.5 A- M 0.5A- (a) Circuit www. (b) Waveform 0 = 4 rad/s t Figure P12.38 Circuit for Problems 12.38 to 12.40.

EXERCISE 1: Consider the waveguide of Example Calculate the phase constant, phase velocity and wave impedance for TE10 and TM11 modes at the operating frequency of 15 GHz. = 192.4 . For Answer: For TE10, B = 615.6 rad/m, u = 1.531 × 108 m/s, TE 529.4 rad/m, u = 1.78 x 10 m/s, TM = 158.8 Q. TM11, B Example 1: A rectangular waveguide with dimensions a = 2.5 cm, b = 1 cm is to operate below 15.1 GHz. How many TE and TM modes can the waveguide transmit? if the guide is filled with a medium characterized by σ = 0, &=4&o Hr = 1° Calculate the cutoff frequencies of the modes.

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