1 / 12

Signals and Networks (SEE 2043) Lecture #18 Topics covered Band Pass Filter Band Reject Filter

Signals and Networks (SEE 2043) Lecture #18 Topics covered Band Pass Filter Band Reject Filter. Objectives. By the end of this lecture, the student must be able to: Understand the characteristics of band pass and band reject filters.

irving
Download Presentation

Signals and Networks (SEE 2043) Lecture #18 Topics covered Band Pass Filter Band Reject Filter

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Signals and Networks • (SEE 2043) • Lecture #18 • Topics covered • Band Pass Filter • Band Reject Filter

  2. Objectives • By the end of this lecture, the student must be able to: • Understand the characteristics of band pass and band reject filters. • Plot the amplitude and phase response of the band pass and band reject filters

  3. Band Pass Filters (BPF) The filter passes signals within a band of frequencies while filtering other frequencies outside this band. Again cutoff frequencies are defined as before. |H(jω)| 1 stopband passband stopband ω 0 ωc1 ωc2 cutoff frequency Ideal magnitude plot of BPF showing passband and stopband, separated by two cutoff frequencies

  4. Band Pass Filters (BPF) • In its simplest form, Band Pass filter can a cascaded structure of LPF and HPF. • LPF- To pass lower frequency range. • HPF- To pass higher frequency range. Vin Vout HPF LPF BPF is a second order filter!!!!

  5. Important parameters of BPF • Two cutoff frequencies, ωc1 and ωc2 • Center frequency @ Resonant frequency: • Bandwidth, β: Bandwidth of the passband • Quality factor, Q: Ratio of the center frequency to the bandwidth 20log10|H(jω)| 0dB -3dB β ωc1 ωo ωc2 ω

  6. L C + V1(s) R Vo(s) + - - Series RLC circuit (BPF) The transfer function for the BPF circuit is: Replacing s=jω:

  7. Band Pass Filter In dB, the magnitude of the transfer function can be written as: The phase angle of the transfer function can be written as: The Bode Plot can be drawn based on the information of type of poles (either zero or complex)

  8. Example (BPF) A filter circuit is shown below. Determine type of filter and the cutoff frequency. R=111.1Ω + V1(s) C=0.001F Vo(s) + - L=50H - Ans: Obtain the Bode Plot and determine the cutoff frequency

  9. Example (BPF) Vin Vout Sketch the Bode Plot for the above transfer function and determine the filter type. Furthermore determine the filter bandwidth.

  10. Band Reject Filters (BRF) The filter passes signals outside the band between the two cutoff frequencies. Complementary function of BPF. |H(jω)| passband stopband passband ωc1 ωc2 ω 0 cutoff frequency Ideal magnitude plot of BRF showing passband and stopband, separated by two cutoff frequencies

  11. Series RLC circuit (BRF) R + V1(s) L Vo(s) + - C - The transfer function for the BPF circuit is: Replacing s=jω:

  12. Band Reject Filter In dB, the magnitude of the transfer function can be written as: The phase angle of the transfer function can be written as: The Bode Plot can be drawn based on the information of type of poles (either zero or complex)

More Related