| 摘要 |
A notch filter (100) includes a parallel coupled delay line (104) and surface acoustic wave resonator (102) which provides a pole at a desired passband. The surface acoustic wave resonator (102) and the delay line (104) are configured to provide a zero at an undesired frequency or stopband. In this way, the notch filter (100) augments the stopband rejection of an associated cascaded surface acoustic wave ladder filter (105). The notch filter (100) also provides a pole at a desired frequency or passband such that losses due to the notch filter (100) at the desired passband are minimized, thereby improving overall insertion loss performance. |
