A 2.0 GHz IQ Imbalance Compensator With Programmable Switch Biases in a Passive Mixer

This brief presents a frequency-independent IQ imbalance compensator with low complexity. The proposed compensator is a revised AND-Type passive mixer with eight programmable switch bias generators. The quadrature phase and gain compensation are simultaneously generated by programming these bias voltages. The generated quadrature compensation is approximately first-order linear to the differential and common mode variances of these bias voltages. The compensator is fabricated within a 2.0 GHz direct-conversion transmitter in a 0.13 ${\mu }\text{m}$ RFCMOS process. The measured image reject ratio adjustment range is 34.8–60.4 dB. All eight 7-step (3-bit D/A converter) bias generators dissipate 1.0 mA at 1.35 V supply.