A mixer with dynamic intermediate frequency in a RF front-end to dynamically adjust the intermediate frequency and method thereof are described. The radio-frequency front-end comprises a band-pass filter, an amplifier, a first mixer unit and a second mixer unit. The band-pass filter receives first RF signal to generate second RF signal. The amplifier amplified the second RF signal and output third RF signal (S.sub.RF). The first mixer unit is used to mix the third RF signal (S.sub.RF) with first frequency signal (S.sub.1) to down convert the third RF signal (S.sub.RF) to an intermediate frequency (IF) and outputs an IF signal (S.sub.IF). The second mixer unit is connected to the first mixer unit in a cascode configuration and has I-channel and Q-channel mixers to transform IF signal (S.sub.IF) to an I-channel signal (S.sub.I) and a Q-channel signal (S.sub.Q). The radio-frequency front-end further comprises a dividing unit for receiving an oscillator signal (S.sub.0) to generate the first, the second and the third frequency signals (S.sub.1, S.sub.2, and S.sub.3) such that the frequency of the first frequency signal (S.sub.1) substantially equals the frequency of the oscillator signal (S.sub.0) divided by two's power of a first non-negative integer (N.sub.1), the frequency of the second and the third frequency signals (S.sub.2, and S.sub.3) substantially both equals the frequency of the oscillator signal (S.sub.0) divided by two's power of a second non-negative integer (N.sub.2), and the second frequency signal (S.sub.2) is approximately 90 degree out of phase with respect to the third frequency signal (S.sub.3).