US Patent 7990231 Delay line

In a band-pass filter of a delay line, an input terminal and a first resonator adjacent to the input terminal are coupled through a capacitor. The first resonator and a second resonator adjacent to the first resonator are coupled through a capacitor. The second resonator and a third resonator adjacent to the second resonator are coupled through an inductance. The third resonator and a fourth resonator adjacent to the third resonator are coupled through a capacitor. The fourth resonator and an output terminal adjacent to the fourth resonator are coupled through a capacitor.