Day 23 - Frequency Dependence and Transfer Functions

Topics Discussed

On day 23 of the ENGR 44 course, we discussed frequency dependence and transfer functions. The transfer function H that we defined in class can be written in four different contexts: 1) Voltage Gain: Vout/Vin 2) Current Gain Iout/Iin 3)Transfer Impedance Vout/Iin 4) Transfer Admittance Iout/Vin. We also discussed the decibel scale. We did several practice problems utilizing these new ideas. (Fig 1 and Fig. 2)

Fig. 1

Fig. 2

Signals with Multiple Frequency Components Lab

In lab today, we made a circuit in which we would analyze the frequency response. We first did some calculations to develop an understanding of how the circuit would work. We also found the transfer function of the circuit. (Fig. 3) We followed the schematic in the lab manual and applied different resistors throughout to gain different results. (Fig. 4)

Fig. 3

Fig. 4

Summary

We were able to successfully create a circuit in which we could analyze the frequency response. We found that as input frequency increased, the gain decreased and vice-versa. By analyzing this circuit, we are able to apply the concepts learned today to future discussions.