Title :
A SAW contiguous filter bank with an m derived ladder
Author :
Misu, Koichiro ; Nagatsuka, Tsutomu ; Wadaka, Shusou
Author_Institution :
Mitsubishi Electr. Corp., Kanagawa, Japan
Abstract :
An m-derived ladder for combining SAW (surface acoustic wave) filters in a contiguous filter bank is proposed. The series element in each m-derived ladder section is composed of a parallel resonant circuit. The input transducer of a SAW filter is used as the shunt element in each section. A pole of attenuation is produced at the resonant frequency of the series element. Thus, the third-harmonic spurious response of the SAW filter is greatly suppressed by setting the pole of attenuation in the vicinity of the third harmonic. A ten-channel version of the filter bank was constructed, operating in the frequency range from 110 to 200 MHz. The insertion loss was 10±1.7 dB, which was as low as that of a constant k ladder filter bank, and the attenuation was greater than 42 dB in the third harmonics from 330 to 600 MHz
Keywords :
surface acoustic wave filters; 110 to 200 MHz; 330 to 600 MHz; SAW contiguous filter bank; input transducer; m derived ladder; parallel resonant circuit; passive filters; resonant frequency; surface acoustic wave; Acoustic transducers; Acoustic waves; Attenuation; Filter bank; Insertion loss; Power harmonic filters; RLC circuits; Resonant frequency; SAW filters; Surface acoustic waves;
Conference_Titel :
Ultrasonics Symposium, 1988. Proceedings., IEEE 1988
Conference_Location :
Chicago, IL
DOI :
10.1109/ULTSYM.1988.49354
