Device for transmitting and/or receiving radio frequency for cognitive radio system, has set of mixing stages mixing filtered signal from band pass filter with local oscillator frequency signal and delivering output frequency signal

摘要

The device has a set of mixing stages (21a, 20) for mixing a radio frequency signal with a local oscillator frequency signal (LO1) and delivering a first intermediate signal. A band pass filter (23) filters the intermediate signal. A second set of mixing stages (24, 25) mixes the signal from the filter with a second local oscillator frequency signal (L02) and delivers a second intermediate signal. A third set of mixing stages (27a, 27a', 28, 29) mixes the filtered signal from another filter (26) with a third frequency signal (L03) and delivers the output frequency signal. Independent claims are also included for the following: (1) a device for transmitting radio frequency (2) a cognitive radio terminal.