Crazy Lab Report

Table of Contents Page Number

1.0 Theory………………………………………………………………………………..1

1.1 The Distortion Analyzer, THD, and SINAD……………………………....2

1.2 AM Receiver Design…...…………………………………………………...2

2.0 Lab Objectives………………………………………………………………………2

3.0 Procedure……………………………………………………………………………3

3.1 Distortion Analyzer, THD, and SINAD Procedure ………………………3

3.2 AM Receiver Design and Test Procedure………………………………..4

4.0 Calculations………………………………………………………………………….6

4.1 Distortion Analyzer, THD, and SINAD Calculations…………………….6

4.2 AM Receiver Calculations………………………………………………..10

5.0 Equations…………………………………………………………………………..12

6.0 Conclusion…………………………………………………………………………14

7.0 Equipment List…………………………………………………………………….15

List of Figures, Graphs, Tables Page Number

Figure 6.1: AM Receiver Design……………………………………………………..11

Graph 6.1: Measured/Predicted SNR(dB) Versus

US Attenuation for 0dB Attenuated DS Signal……………………………………….8

Graph 6.2: Measured/Predicted SNR(dB) Versus

US Attenuation for 6dB Attenuated DS Signal……………………………………….9

Graph 6.3: Measured/Predicted SNR(dB) Versus US Attenuation for 12dB Attenuated DS Signal………………………………………………………………….10

Table 6.1: Signal Powers and Frequencies ………………………………………….6

Table 6.2: Signal Sideband Power Results…………………………………...……...6

Table 6.3: Reference Power Results………………………………………………….6

Table 6.4: Measured and Predicted SNR(dB) for 0dB Attenuated DS Signal……7

Table 6.5: Measured and Predicted SNR(dB) for 6dB Attenuated DS Signal……8

Table 6.6: Measured and Predicted SNR(dB) for 12dB Attenuated DS Signal…..9

Table 6.7: AM Receiver Design Results…………………………………………….10

Table 6.8: Signal Powers and Frequencies…………………………………………11

Table 6.9: Overall and Amplifier Noise Figures…………………………………….12

Table 6.10: Devices Used…………………………………………………………….15

1.0 Theory

1.1 The Distortion Analyser, THD, and SINAD

A distortion analyzer is an instrument that allows measurement of desired signal power and noise power of an audio signal that has both noise and a desired signal. The total harmonic distortion is defined as the ratio of RMS noise to RMS signal and noise. The total harmonic distortion is calculated in dB using Equation 6.1 below:

Equation 6.1:

Another term called the SINAD is defined as the ratio of signal power plus noise to the noise power. The SINAD in dB is equal to the negative THD in dB. The SINAD as a ratio is equal to the signal to noise ratio plus one. Equation 6.2 can be used to calculate the SNR if the SINAD in decibels is known:

Equation 6.2:

1.2 AM Receiver Design

Many of the theories used for designing an AM receiver are developed