Download CEET 3010 Laboratory 7: Analyzing Filters in the S-Domain and more Lab Reports Microelectronic Circuits in PDF only on Docsity! Laboratory 7 CEET 3010 Fall 2008 Filters Purpose: Introduce students to circuit analysis in the S-Domain through the analysis of a filter. Equipment and Components: • Computer with MATLAB and PSpice. • Prototyping board, Multimeter, Signal Generator, Oscilloscope. • Resistors: 400 Ω, 1 kΩ, 80 kΩ, and 160 kΩ • Capacitors: 2 – 0.01 µF, 47 nF. • Op Amp: LM 321 or equivalent All computers in the CEET computer lab (B4 408) have MATLAB and PSpice Preliminary: Circuits constructed with capacitors and inductors respond differently to various sinusoidal frequencies. As the impedance of a capacitor = 1/jωC and an inductor = jωL change with frequency, so to does the overall gain / attenuation that the circuit presents. This relationship of gain / attenuation to frequency, K(s) where jω→s, is called the frequency response of a system. Typically plotted in dB on a log scale, the frequency response is commonly called the Bode diagram. Depending upon the basic shape of the frequency spectrum, circuits can be classified into five basic types; Low Pass filter, High Pass filter, Band Pass filter, Band Notch filter, or a combination of the previous four. Low Pass filters present no attenuation or a gain at low frequency and present a high attenuation at high frequencies. High Pass filters present high impedance or attenuation at low frequencies and a gain or no attenuation at high frequencies. Band Pass and Band Notch have a limited number of frequencies at which gain or attenuation is presented. The region in which frequencies are passes with minimal attenuation is called the Pass Band. The width of the Pass Band is also called the Bandwidths (BW), and is defined in multiple ways. The most common definition for the Bandwidth is the range of frequencies in which over half of the power is allowed to pass through the circuit, where ωc1, and ωc2 are called the corner frequencies, cut-off frequencies half power points, and/or the 3dB point. It should also be pointed out that the half power point occurs when the voltage is 0.707 times the peak value, 1/√2 Vp. If the system is a low or high pass filter then one of the corner frequencies is at DC or ∞. 1. For Figure 7.1 perform the following: a. Converting the circuit to the S-domain b. Derive an expression for Vo(s) verses Vi(s). This is commonly called the transfer function c. Using MATLAB plot the amplitude of the transfer function as a function of frequency s→jω and include them in your lab book. Also on the plots locate the corner frequencies and calculate the bandwidth. Hint: To plot the frequency response of a transfer function first define the function using TF and then plot the response using BODE (see Lab 6) d. Identify the type of filter.
