21. A CTCSS decoder is based on a very narrow bandpass filter which passes the desired CTCSS tone. 22. Depending on the values you choose, it could be a bandpass filter or a notch filter. 23. The volume Bragg grating technology is also used to design tunable bandpass filters for various light sources. 24. Theory of microwave narrow-band bandpass filters that have Chebyshev frequency response is stated in monograph. 25. For example, RLC bandpass filter characteristics can be realized with capacitors, resistors and operational amplifiers without using inductors. 26. Bandpass filters are often used in astronomy when one wants to observe a certain process with specific associated spectral lines.27. A subsequent bandpass filter selects the desired harmonic frequency and removes the unwanted fundamental and other harmonics from the output. 28. The output signals from the bandpass filters are then lowpass translated to reduce the bandwidth, which reduces the sampling rate. 29. Therefore, the Earth-ionosphere waveguide behaves like a bandpass filter , selecting this band out of a broadband signal. 30. This animation shows how the resolution bandwidth of a swept-tuned spectrum analyzer is affected by the IF bandpass filter .
