A Fully Integrated 3 to 5 GHz CMOS Mixer with Active Balun for UWB Receiver

A fully integrated 3-to-5 GHz CMOS mixer for UWB system is presented in this paper. The designed mixer utilizes a dynamic injection circuit to reduce noise figure. In order to adjust the conversion gain, linearity, and noise figure easily, we connect a capacitor and a resistor in series between the drain and the gate of a NMOS transistor. A designed active balun which converts the single-ended input signals to differential signals for UWB is also proposed. The fully integrated mixer is designed and fabricated in 0.18 mum TSMC technology with 1.27 times 1.14 mm² die size. With -30 dBm for 3 ~ 5 GHz input RF, 0 dBm for 3-5 GHz input LO, and 100 MHz output baseband frequency, the simulated chip achieves 5 ~ 13 dB conversion gain, -4 ~ 2.4 dBm input intercept point (IIP3) and 11.7 ~13.7 dB noise figure for 1.8 V supply voltage