Some of the important filter attributes are (1) controlling noise by not allowing out-of-band noise to propagate in a circuit; (2) keeping signals outside the transmit band, especially harmonics, from...Some of the important filter attributes are (1) controlling noise by not allowing out-of-band noise to propagate in a circuit; (2) keeping signals outside the transmit band, especially harmonics, from being transmitted; and (3) presenting only signals in a specified band to active receive circuitry. In the case of a bandpass filter, each inductor and capacitor of the lowpass prototype becomes a resonator that is coupled to another resonator.
