Filter arrangement, e.g. for radio transceiver, has first impedance which is connected at first connection to input and with first resonant frequency with second impedance connected at first connection to input of filter

摘要

The filter has a first impedance (20) which is connected at a first connection (21) to an input (2) and with a first resonant frequency (f1). A second impedance (50) is connected at a first connection (51) to the input of filter with a second resonant frequency (f2), which is higher than the first. A subtraction unit (4) having two inputs (5, 6) and a first output (13) is connected to the first impedance. The second input is connected to the second impedance and connected to the filter arrangement with a first connection (7) of the output (13) connected to the first output (3). Independent claims are included for : (1) a transceiver using a filter according to the invention; (2) use of a filter according to the invention in the receive path of a mobile radio communications device; and (3) a method for filtering an input signal.