Patent attributes
A mixer includes first to fourth NMOS transistors, first and second switches, first to fourth current sources, a first impedance and a second impedance. The first NMOS transistor has a drain coupled to the first impedance and a drain of the third NMOS transistor, and a gate for receiving a positive input signal. The second NMOS transistor has a drain coupled to the second impedance and a drain of the fourth NMOS transistor, and a gate for receiving a negative input signal. Gates of the third and fourth NMOS transistors respectively receive the negative and positive input signals. The first switch is coupled between sources of the first and second NMOS transistors. The second switch is coupled between sources of the third and fourth NMOS transistors. The first to fourth current sources maintain constant currents flowing through the sources of the first to fourth NMOS transistors, respectively.
