| 摘要 |
750,418. Filters. PATELHOLD PATENTVERWERTUNGS & ELEKTRO-HOLDING AKT.-GES. June 18, 1953 [June 20, 1952], No. 16865/53. Class 40 (8). A band-pass filter for use with waveguides, and coaxial or parallel-wire lines comprises several resonant systems connected by #/4 lengths of transmission line and having a characteristic impedance which varies symmetrically from the centre of the filter to both ends. As shown in Fig. 4, four resonators each comprising a casing 7, a tube 4, and a pin 6 which is displaced by gears 9, 10 are arranged in parallel across a coaxial line 1, 2. The resonators may be provided with additional tuning bolts 8. The characteristic impedances Z<SP>1</SP>, Z<SP>2</SP> of the sections are arranged to decrease from the centre to the ends of the filter. By suitable selection of the values of thes impedances it is stated that the filter may be used as an impedance transformer. In a modification (Fig. 5, not shown) the resonators are arranged in series with the impedances increasing from the centre to the ends. It is stated that lumped elements may be used in the resonant systems. |
