2026 MECH 370 Lab 6 Experiment (Frequency Response of Passive Electrical Filters) Concordia University

2026 MECH 370 Lab 6 Experiment (Frequency Response of Passive Electrical Filters) Concordia University Lab 6: Frequency Response of Passive Electrical Filters Lab Section EI – X Winter 2025 Professor Christopher Yee Wong Concordia University Montreal, QC, Canada CONTENTS CONTENTS 2 LIST OF TABLES AND FIGURES 3 OBJECTIVE 4 INTRODUCTION 4 PROCEDURE 5 RESULTS 6 EXPERIMENTAL 6 SIMSCAPE 12 SAMPLE CALCULATIONS 23 DISCUSSION 24 CONCLUSION 26 REFERENCES 26 LIST OF TABLES AND FIGURES Table 1: Experimental Results for LC Low-Pass Circuit Table 2: Experimental Results for LC High-Pass Circuit Table 3: Experimental Results for Single Section RC LPF Circuit Table 4: Experimental results for Twin Section RC LPF Table 5: Experimental Results for BPF Circuit Figure 1: Radian Frequency vs Magnitude Ratio for LC Low and High Pass Circuit Figure 2: Radian Frequency vs Magnitude Ratio for Single and Twin RC LPF Figure 3: Radian Frequency vs Magnitude Ratio for BPF circuit Figure 4: Radian Frequency vs Magnitude Ratio for Double Resonance Circuit Figure 5: Figure 6-2 Simscape [1] Figure 6: Simulation for 1000hz of figure 6-2 Figure 7: Simulation for 5000hz of figure 6-2 Figure 8: Simulation for 10000hz of figure 6-2 Figure 9: Simulation for 15000hz of figure 6-2 Figure 10: Simulation for 20000hz of figure 6-2 Figure 11: Figure 6-4 Simscape [1] Figure 12: Simulation for 1000hz of figure 6-4 Figure 13: Simulation for 5000hz of figure 6-4 Figure 14: Simulation for 10000hz of figure 6-4 Figure 15: Simulation for 15000hz of figure 6-4 Figure 16: Simulation for 20000hz of figure 6-4 Figure 17: Figure 6-6 Simscape [1] Figure 18: Simulation for 1000hz of figure 6-6 Figure 19: Simulation for 5000hz of figure 6-6 Figure 20: Simulation for 10000hz of figure 6-6 Figure 21: Simulation for 15000hz of figure 6-6 Figure 22: Simulation for 20000hz of figure 6-6 Figure 23: Figure 6-4 Circuit Analysis Figure 24: Bode Diagram for Single Section RC Figure 25: Bode Diagram for Twin Section RC OBJECTIVE The objective of this lab was to analyze the steady-state frequency response of passive RC and LC filters, explore their resonance characteristics, and compare the experimental results with those from computer simulations. INTRODUCTION An electrical filter can be described as a signal processing circuit which transmits sinusoidal waves within a certain range of frequencies. Waves that are found within said frequency are known as the passband while waves that are out of the range of frequency are referred to as the stopband and are rejected. A passive filter is an example of a filter that uses resistors (R), inductors (L), and capacitors (C), and operates without requiring active components such as amplifiers. This filter can be divided into several categories, including low-pass filters (LPFs), high-pass filters (HPFs), band-pass filters (BPFs), and band-reject filters (BRFs). Each type exhibits unique frequency-response behavior determined by its design and the way its resistive and reactive elements interact. Resonance is a key concept in which it is responsible for the range of frequencies a circuit will either accept or reject. Resonance can be described as when output value for certain circuits reaches a peak value at some specific frequency. This occurs when the inductive reactance balances out the capacitive reactance, and thus results in an impedance that is purely resistive, leading to either a peak or a dip in the frequency response. The quality factor Q, expressed as Q=, represents how well-defined the resonance is and serves as a measure of the circuit's energy efficiency. LC type circuits utilize resonance between L and C and have two types of circuits low pass and high pass. Low pass circuits resonate frequency between the natural resonant frequency which is as follows While high pass frequencies allow frequencies in above to pass, this is also based on the resonance concept mentioned above. In comparison, RC filters lack inductive components and offer gradual signal attenuation without exhibiting any resonance. For RC low-pass filters, the cutoff frequency is given by ω =, with R and C setting the system's time constant. Twin-section RC filters, due to their higher order, provide steeper attenuation than single-section designs. Bandpass and band reject circuits are LCR circuits that have parallel resonance or series resonance in their LC branches. In these filters the bandpass or stopband will be centered around the natural frequency of the series parallel resonance A double resonance circuit is a circuit which includes two resonance frequencies. These circuits have resonance that occur around the frequency