NAME: YASIR AFNAN REGISTRATION NUMBER: 21PWELE 5879 SUBJECT: CIRCUIT ANALYSIS 2 LAB INSTRUCTOR: MUHAMMAD FAROOQ SIR DEPARTMENT: ELECTRICAL COMMUNICATION SECTION: C 1|Page LAB NUMBER: 11 To study the frequency RC high filter pass filter THEORY: HIGH PASS FILTER: A high pass filter is an electronic filter that passes signal with a frequency higher than a certain cutoff frequency and attenuates signals with frequencies lower than the cutoff frequency the amount of attenuation for each frequency depends on the filter design. A high pass filter is usually modeled as linear time invariant system. OR We can simply define as a high pass filter is a filter which passes high frequency signal and blocks or impedes, low frequency signals.in other words ,high frequency go through much easier and low frequency signal have a much harder getting through ,which is why its high pass filter, HIGH PASS FILTER USES: The high pass filter application mainly include the following 1- These filter are used in speaker for amplification. 2- High pass filter is used in to remove unwanted sound near to the lower end of audible range. 3- To prevent the amplification of dc current that harm the amplifier, high pass filter are used for ac coupling . 4- High pass filter in image processing high pass filter are used in image processing for sharpening the details.by applying these filter over an image we can exaggerate every tiny part of detail in an image. Cutoff frequency: The cutoff frequency of a filter is the frequency at which the magnitude of the output voltage signal drops by a factor 70%. Can be calculated in case of RC 𝑓𝑐 = 1⁄2𝑅𝜋𝑐 And if we use the inductor 𝑓𝑙 = 𝑅⁄2𝜋𝐿 2|Page Decibels: Decibel is logarithmic expression used in filter application as a unit of gain or loss .characteristic of logarithmic operation, processes involving multiplication, division are reduced to additions and subtractions, that in many but all cases is advantageous because the calculation is simpler. 𝑋 𝑋𝑑𝑏 = 20 log10 (𝑋 ) 0 𝑋 𝑋𝑑𝑏 = 10 log10 (𝑋 ) 0 This is for voltage This is for power Observation and calculation: S.NO Cutoff freq 𝑣 Av= 0⁄𝑣𝑖 𝑓𝑐 -1 40 0.04 02 50 0.57 03 70 0.72 04 4000 1 05 5000 1.1 𝑉0 Is the output voltage and VI is input voltage which should be fixed 3|Page GRAPHICALLY: AV 1.2 1 0.8 0.6 0.4 0.2 0 -1000 0 1000 2000 3000 4000 5000 6000 As there is some error in values this why the graph is a little bit wrong. But the behavior is correct if we see on low frequency we have values nearly equal to zero while on rising frequency it results in increasing the graph. 4|Page 5|Page