| 摘要 |
<p>The present invention is a hybrid RF-digital signal processor-based filter for multiband radio architectures, systems capable of spectrum re- farming and software defined radios It performs low-loss frequency agile multiple notch filtering at RF where a large dynamic range exists at a filter input between signals in a stopband and passband It is a frequency dependent signal attenuation apparatus having two paths connected together by directional couplers The first path comprising a component such as a delay component or duplexer The second path comprising, in series, a down converter, a digital filter, an up converter, and a bandstop filter At the output of a power amplifier, the invention can be used to attenuate spurs, or noise within bands with strict emission constraints At the input of a low noise amplifier, the invention can be used to attenuate blockers and transmitter noise outside of the receiver passband.</p> |
