jeryxin
Newbie level 6
quadrature upconversion mixer
I simulated a gilbert cmos quadrature upconversion mixer in ADS. According to 'RF transmitter architectures and circuits' by Razavi, the output frequency should be cos(freq_LO-freq_BB). However, my HB simulation gave both (freq_LO-freq_BB) and (freq_LO+freq_BB) components together with the same amplitude. After that, I plotted transient simulation result in frequency domain, the difference of (freq_LO-freq_BB) and (freq_LO+freq_BB) components is about 50dbc. Obliviously, transient simulation gave me a correct answer, but I wonder why HB simulation not!
I simulated a gilbert cmos quadrature upconversion mixer in ADS. According to 'RF transmitter architectures and circuits' by Razavi, the output frequency should be cos(freq_LO-freq_BB). However, my HB simulation gave both (freq_LO-freq_BB) and (freq_LO+freq_BB) components together with the same amplitude. After that, I plotted transient simulation result in frequency domain, the difference of (freq_LO-freq_BB) and (freq_LO+freq_BB) components is about 50dbc. Obliviously, transient simulation gave me a correct answer, but I wonder why HB simulation not!