A Highly Linear 1-GHz CMOS Downconversion Mixer

A highly linear, closed loop CMOS architecture is demonstrated for the mixing of RF waveforms to baseband as sampled-data signals. In converting a 915 MHz RF waveform to a 20 MHz spread spectrum baseband signal, the measured third-order intercept lies at +27 dBm of input power. As the 1-μm CMOS prototype dissipates only 12 mW from a 5V supply, and is capable of operation at 3V, it is expected to be of use in advanced handheld wireless receivers.