摘要 |
<p>A filter structure (1090, 1100, 1200) comprises a first piezoelectric resonator (1021a), whose resonance frequency is a first resonance frequency and which is connected to an input conductor (1030a, 1030b). In order to increase the power handling capacity of the filter structure, it comprises other piezoelectric resonators connected in series with the first piezoelectric resonator. In this plurality (1020, 1110, 1220) of piezoelectric resonators, each resonator has a resonance frequency substantially equal to the first resonance frequency. The plurality (1020, 1110, 1220) of piezoelectric resonators is connected to the rest of the filter structure only through the first piezoelectric resonator (1021a) at one end of said plurality and through a second piezoelectric resonator (1021b), which is at the other end said plurality. The impedance of said plurality is arranged to match the impedance level of the filter structure. An arrangement for transmitting and for transmitting and receiving radio frequency signal is also described.</p> |