| 摘要 |
<p>The invention relates to a highly-selective band rejector making it possible to reject a narrow band centred on a predetermined frequency Fo, comprising: - a coupler (5) termed the -3dB quadrature coupler; - a first and a second identical bandpass filter (6 and 7) having high selectivity, tuned to the frequency Fo and each loaded with an impedance (R1 and R2) suitable for the frequency Fo. The impedance at the input (1) and the impedance at the output (4) of the band rejector thus constructed remain suitable throughout the frequency range in which the rejector is used. Application to radio-receivers and to stations containing several radio-receivers, in order to eliminate one or more fixed jamming frequencies transmitted by transmitters situated nearby. <IMAGE></p> |
