| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To restrict occurrence of ripples within a passband while also aiming to expand the passband in configuring a bandpass filter by using a longitudinal mode resonance filter. <P>SOLUTION: Three filter units 1-3 are connected in parallel between an input port 21 and an output port 22, in which a resonance point f<SB POS="POST">21</SB>on the high-pass side of a first filter unit 1 and a resonance point f<SB POS="POST">12</SB>on the low-pass side of a second filter unit 2 are laid one on top of another, and also a resonance point f<SB POS="POST">22</SB>on the high-pass side of the second filter unit 2 and a resonance point f<SB POS="POST">13</SB>on the low-frequency side of a third filter unit 3 are laid one on top of another. The first filter unit 1 and the third filter unit 3 are composed so that electric signals extracted from the output port 22 are in the same phase with each other. On the other hand, the second filter unit 2 is composed so that an electric signal extracted from the output port 22 is in opposite phase with those of the first filter unit 1 and the third filter unit 3. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
