A Ka-band low-noise amplifier using semicircle stacked-GCPW transmission line

A high-gain Ka-band 0.18-μm CMOS low-noise amplifier with semicircle stacked grounded coplanar waveguide (SCS-GCPW) structure transmission line is proposed. SCS-GCPW transmission line is adopted to reduce the signal loss by shaping the electric fields under the signal line especially at microwave and millimeter wave applications. The SCS-GCPW demonstrated a similar electric field distribution of coaxial cable and achieved a substrate dielectric attenuation constant of 0.075 Np/m. It is superior to 0.081 Np/m and 0.144 Np/m of traditional microstrip transmission line and CPW transmission line, respectively. By adopting the low loss SCS-GCPW transmission line, the Ka-band LNA demonstrated a 24.5 dB gain together with a noise figure (NF) of 7.5 dB at 33 GHz operation. The measured output power 1 dB compression point (P1 dB) was −2 dBm. The dc power consumption was 40 mW and chip size was 0.6 × 1 mm2 for this Ka-band LNA. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1131–1134, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25910