| 摘要 |
<p>1. Filter having a switchable bandwidth and formed from at least one part filter, having reactance elements (C1, C3, ... C(n-2); Cn/C2; C4; ... C(n-1)/L21; L41; ... L(n-1)1), which are in each case located in the series and shunt branch, in which inductances located in the series branch in each case exhibit one tap and are switchable to this by means of switching diodes, characterized in that a) in each part filter - a termination of the series branch and a termination (B) of the switchable inductance (L21; L41; ... L(n-1)1) is connected to a diode (D2; D4; ... D(n-1)) and - the said termination of the series branch and the tapping point (M) of the switchable inductance is connected to a further diode (D1; D3; ... D(n-2)), which is connected in antiparallel with the first diode, and that b) a potential which is higher (+ UB ) or lower (earth) with respect to the maximum or minimum operating direct voltage of the generator (G) is applied via a change-over switch (S) for generating a different voltage gradient for a first (fB1 ) or a second (fB2 ) cut-off frequency.</p> |
