摘要 |
The invention proposes a filtering device having a frequency response which is symmetrical, using asymmetrical filters coupled by transposition means. The advantageous characteristics of the asymmetrical filters are retained and the faults associated with the asymmetry are eliminated. The asymmetrical filters are, for example, quartz filters. The invention also proposes an external transmission and reception unit, using the filtering device with the application of the filtering method.
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