filters in radio frequency
DESCRIPTION
RFCDTRANSCRIPT
![Page 1: Filters in Radio Frequency](https://reader036.vdocuments.us/reader036/viewer/2022062313/55cf8ee8550346703b96e6ba/html5/thumbnails/1.jpg)
FILTERS & THEIR PARAMETERS
Rachit Manchalwar | D063
![Page 2: Filters in Radio Frequency](https://reader036.vdocuments.us/reader036/viewer/2022062313/55cf8ee8550346703b96e6ba/html5/thumbnails/2.jpg)
WHAT ARE FILTERS? Filters are circuits which separate and allow only signals of specific frequencies to pass through.
4 categories – • Low Pass• High Pass• Band Pass• Band Stop
![Page 3: Filters in Radio Frequency](https://reader036.vdocuments.us/reader036/viewer/2022062313/55cf8ee8550346703b96e6ba/html5/thumbnails/3.jpg)
LOW FREQUENCY FILTERS• Frequency range in kHz
• Plot of Gain v/s. Frequency
![Page 4: Filters in Radio Frequency](https://reader036.vdocuments.us/reader036/viewer/2022062313/55cf8ee8550346703b96e6ba/html5/thumbnails/4.jpg)
LOW FREQUENCY FILTERS
![Page 5: Filters in Radio Frequency](https://reader036.vdocuments.us/reader036/viewer/2022062313/55cf8ee8550346703b96e6ba/html5/thumbnails/5.jpg)
HIGH FREQUENCY FILTERS• Frequency Range of GHz• Plot of Attenuation (α) v/s. Frequency
![Page 6: Filters in Radio Frequency](https://reader036.vdocuments.us/reader036/viewer/2022062313/55cf8ee8550346703b96e6ba/html5/thumbnails/6.jpg)
HIGH FREQUENCY FILTERS
![Page 7: Filters in Radio Frequency](https://reader036.vdocuments.us/reader036/viewer/2022062313/55cf8ee8550346703b96e6ba/html5/thumbnails/7.jpg)
FILTER CIRCUITS
![Page 8: Filters in Radio Frequency](https://reader036.vdocuments.us/reader036/viewer/2022062313/55cf8ee8550346703b96e6ba/html5/thumbnails/8.jpg)
FILTERS TO BE DISCUSSED1. Butterworth (Binomial) Filter
2. Chebyshev Filter
![Page 9: Filters in Radio Frequency](https://reader036.vdocuments.us/reader036/viewer/2022062313/55cf8ee8550346703b96e6ba/html5/thumbnails/9.jpg)
TYPES OF FILTERS
![Page 10: Filters in Radio Frequency](https://reader036.vdocuments.us/reader036/viewer/2022062313/55cf8ee8550346703b96e6ba/html5/thumbnails/10.jpg)
BUTTERWORTH FILTERS Also called as Maximally Flat Filter. No ripple permitted in attenuation profile Insertion Loss can be determined from the loss factor;
N = Order of the filterΩ = Normalized frequency
![Page 11: Filters in Radio Frequency](https://reader036.vdocuments.us/reader036/viewer/2022062313/55cf8ee8550346703b96e6ba/html5/thumbnails/11.jpg)
BUTTERWORTH FILTERS
![Page 12: Filters in Radio Frequency](https://reader036.vdocuments.us/reader036/viewer/2022062313/55cf8ee8550346703b96e6ba/html5/thumbnails/12.jpg)
ATTENUATION PROFILE FOR BUTTERWORTH FILTER FOR VARIOUS FILTER ORDERS
![Page 13: Filters in Radio Frequency](https://reader036.vdocuments.us/reader036/viewer/2022062313/55cf8ee8550346703b96e6ba/html5/thumbnails/13.jpg)
CHEBYSHEV FILTERS Also called as Equiripple Filter.
Insertion Loss will be as folllows;
IL = , where•TN(Ω) = , for |Ω|≤1•TN(Ω) = , for |Ω|≥1
![Page 14: Filters in Radio Frequency](https://reader036.vdocuments.us/reader036/viewer/2022062313/55cf8ee8550346703b96e6ba/html5/thumbnails/14.jpg)
CHEBYSHEV FILTERS
![Page 15: Filters in Radio Frequency](https://reader036.vdocuments.us/reader036/viewer/2022062313/55cf8ee8550346703b96e6ba/html5/thumbnails/15.jpg)
ATTENUATION RESPONSE FOR CHEBYSHEV
![Page 16: Filters in Radio Frequency](https://reader036.vdocuments.us/reader036/viewer/2022062313/55cf8ee8550346703b96e6ba/html5/thumbnails/16.jpg)
COMPARISON
![Page 17: Filters in Radio Frequency](https://reader036.vdocuments.us/reader036/viewer/2022062313/55cf8ee8550346703b96e6ba/html5/thumbnails/17.jpg)
CONCLUSION Chebyshev filter has the steepest slope of the attenuation profile.
Linear phase filter exhibits lowest roll-off.
Thus, Chebyshev is selected when:1. If a sharp transition from PB to SB is required2. Ripples can be tolerated
Also, its Attenuation at cut-off frequency is equal to the ripple size in PB.
Linear phase can be used for modulation and mixer circuits.
![Page 18: Filters in Radio Frequency](https://reader036.vdocuments.us/reader036/viewer/2022062313/55cf8ee8550346703b96e6ba/html5/thumbnails/18.jpg)
A COMPARISON BETWEEN BUTTERWORTH AND CHEBYSHEV
Butterworth Filter
• Magnitude response decreases with increase in frequency (from 0 - ∞)
• Width of Transition band is more.
• The order of filter is more, for same specifications, as compared to chebyshev. Hence no. of components required to construct a filter are less.
Chebyshev Filter
• Magnitude response fluctuates or shows ripples in PB and SB depending on the type of filter.
• Width of Transition band is comparatively less.
• The order of filter is less, for same specifications, as compared to chebyshev. Hence no. of components required to construct a filter are more.
![Page 19: Filters in Radio Frequency](https://reader036.vdocuments.us/reader036/viewer/2022062313/55cf8ee8550346703b96e6ba/html5/thumbnails/19.jpg)
PARAMETERS OF FILTERS Insertion Loss: Power Loss in PassbandIL =
WherePIN = Input PowerPL = Load Power = Reflection Coefficient
![Page 20: Filters in Radio Frequency](https://reader036.vdocuments.us/reader036/viewer/2022062313/55cf8ee8550346703b96e6ba/html5/thumbnails/20.jpg)
PARAMETERS OF FILTERS Ripple: Difference between maximum and minimum amplitude response in dB or nepers. We can control the amplitude of the ripple in Chebyshev Filters
![Page 21: Filters in Radio Frequency](https://reader036.vdocuments.us/reader036/viewer/2022062313/55cf8ee8550346703b96e6ba/html5/thumbnails/21.jpg)
PARAMETERS OF FILTERS Bandwidth: Difference between the upper and lower cut-off frequencies in Band Pass FiltersRecorded at 3dB attenuation points above the passband.BW3dB =
![Page 22: Filters in Radio Frequency](https://reader036.vdocuments.us/reader036/viewer/2022062313/55cf8ee8550346703b96e6ba/html5/thumbnails/22.jpg)
PARAMETERS OF FILTERS Shape Factor: Sharpness of filter responseRatio of 60dB and 3dB bandwidths SF =
![Page 23: Filters in Radio Frequency](https://reader036.vdocuments.us/reader036/viewer/2022062313/55cf8ee8550346703b96e6ba/html5/thumbnails/23.jpg)
PARAMETERS OF FILTERS Rejection:
Rejection is the finite attenuation level in practical filtersDue to limited number of filter componentsUsually 60dB (since can be readily combined with shape factor)
![Page 24: Filters in Radio Frequency](https://reader036.vdocuments.us/reader036/viewer/2022062313/55cf8ee8550346703b96e6ba/html5/thumbnails/24.jpg)
PARAMETERS OF FILTERS Quality Factor: Ratio of average stored energy to energy loss per cycle at resonant frequency.
![Page 25: Filters in Radio Frequency](https://reader036.vdocuments.us/reader036/viewer/2022062313/55cf8ee8550346703b96e6ba/html5/thumbnails/25.jpg)
ATTENUATION PROFILE OF BPF
![Page 26: Filters in Radio Frequency](https://reader036.vdocuments.us/reader036/viewer/2022062313/55cf8ee8550346703b96e6ba/html5/thumbnails/26.jpg)
ATTENUATION AND ORDER - IDEAL
![Page 27: Filters in Radio Frequency](https://reader036.vdocuments.us/reader036/viewer/2022062313/55cf8ee8550346703b96e6ba/html5/thumbnails/27.jpg)
ATTENUATION AND ORDER - PRACTICAL
![Page 28: Filters in Radio Frequency](https://reader036.vdocuments.us/reader036/viewer/2022062313/55cf8ee8550346703b96e6ba/html5/thumbnails/28.jpg)
ATTENUATION AND ORDER Ideally, there should infinite attenuation from cut-off frequency
Practically not attainable
Steep transition from PB to SB can be achieved by increasing order of filter.
Steeper transition to stopband comes at a price – higher ripple in passband
![Page 29: Filters in Radio Frequency](https://reader036.vdocuments.us/reader036/viewer/2022062313/55cf8ee8550346703b96e6ba/html5/thumbnails/29.jpg)
THANK YOU