| 摘要 |
PURPOSE:To avoid the effect of bulk waves and to achieve a filter with excellent characteristics, by locating in parallel an output transducer at a region other than the extension of an input transducer via a multistrip coupler, in a multichannel filter. CONSTITUTION:Surface acoustic waves generated 2 through the input of a composite signal from a tuner are converted for the transmission line with a linear coupler 3 and converted into electric energy. The energy is equally divided into transducers 4, 5 and greatly attenuates a sound carrier wave through a signal including carrier chrominance wave signals CC and video carrier wave PC. A filter consisting of the output transducer 5 passes through only the SC and PC and greatly attenuates signals other than the PC. The filter characteristics depend on the crossing width of reed screen electrode of each transducer and pitch and the like and an output signal is picked up from terminals 41-52. With this constitution, bulk waves passing through the coupler 3 do not give any effect on the output transducer and give excellent frequency characteristics and spurious characteristics. |
