Signal & Comm. Chapter 03_The Fundamentals of Electronics.pptx

The Fundamentals of Electronics

1. Chapter 2 The Fundamentals of Electronics 9/9/2024 1

2. Topics Covered in Chapter 2-1: Gain, Attenuation, and Decibels 2-2: Tuned Circuits 2-3: Filters 2-4: Fourier Theory 9/9/2024 2

3. 2-1: Gain, Attenuation, and Decibels Most circuits in electronic communication are used to manipulate signals to produce a desired result. All signal processing circuits involve: Gain Attenuation 9/9/2024 3

4. 2-1: Gain, Attenuation, and Decibels Gain  Gain means amplification. It is the ratio of a circuit’s output to its input. An amplifier has gain. 9/9/2024 4

5. 2-1: Gain, Attenuation, and Decibels Most amplifiers are also power amplifiers, so the same procedure can be used to calculate power gain AP where P in is the power input and Pout is the power output. Power gain ( Ap ) = P out / P in Example: The power output of an amplifier is 6 watts (W). The power gain is 80. What is the input power? Ap = Pout / Pin therefore Pin = Pout / Ap Pin = 6 / 80 = 0.075 W = 75 mW 9/9/2024 5

6. 2-1: Gain, Attenuation, and Decibels An amplifier is cascaded when two or more stages are connected together. The overall gain is the product of the individual circuit gains. Example: Three cascaded amplifiers have power gains of 5, 2, and 17. The input power is 40 mW. What is the output power? 9/9/2024 6

7. 2-1: Gain, Attenuation, and Decibels Attenuation Attenuation refers to a loss introduced by a circuit or component. If the output signal is lower in amplitude than the input, the circuit has loss or attenuation. The letter A is used to represent attenuation Attenuation A = output/input = V out/ V in Circuits that introduce attenuation have a gain that is less than 1. With cascaded circuits, the total attenuation is the product of the individual attenuations. 9/9/2024 Applied Collage, UOH 7

8. 2-1: Gain, Attenuation, and Decibels A voltage divider introduces attenuation. 9/9/2024 8

9. 2-1: Gain, Attenuation, and Decibels Total attenuation is the product of individual attenuations of each cascaded circuit. 9/9/2024 9