| 摘要 |
<p>The present invention relates to a tunable filter device for providing a tunable band pass characteristics for the receive path of a multi-band front-end module. According to the invention is proposed, a distributed, wide-band amplifier with a low-frequency cut-off and a high-frequency cut-off in combination with a LCR network, of which wide-band amplifier the DC blocking capacitors define the low-frequency cut-off of the filter device, whilst the high-frequency cut-off is determined by the cut-off frequency of the artificial input and output transmission lines of the LCR network. In one embodiment, additional capacitors are coupled in parallel to the DC blocking capacitors of the LCR network, switchable by MOS transistors as switching elements. Accordingly, in a certain embodiment it is proposed to allow tuning of the low- and the high-frequency cut-off by programming with a digital control command.</p> |
