60-GHz CMOS Down-Conversion Mixer with Slow-Wave Matching Transmission Lines

A cascade CMOS mixer is fabricated to exploit the unlicensed band around 60 GHz. This topology avoids the need for area-consuming power combining and uses simple matching with slow-wave transmission lines (SWTL). SWTL has a higher quality factor and allows area reduction. The circuit is fabricated in standard digital 90-nm CMOS and has a radio frequency (RF) return-loss more than 10 dB between 46 GHz and 64 GHz. At RF of 60 GHz, intermediate frequency (IF) of 4 GHz and local oscillator (LO) power of 1.5 dBm, the conversion loss is 1.2 dB and an input-referred 1-dB compression point of 0.5 dBm was measured. The length reduction of the transmission lines achieved is 47% and the resulting chip occupies an area of 0.61 mm x 0.80 mm with comparable performance to other works.