| 摘要 |
<p>In a radiofrequency filter (34; 35; 36) there is a port (34a; 34b; 34c) by means of which it is connected to an external component (14; 17; 21) and the impedance of which is adjusted by internal filter circuits so as to correspond to the impedance of the external component (Zant, ZRX, ZTX) at the operating frequency. The filter may for example be a duplex filter (34), in which case the internal impedance matching may be employed at the antenna port (34a), at the reception port (34b) and/or at the transmission port (34c). <IMAGE></p> |
