Wideband Inductorless Balun-LNA Employing Feedback for Low-Power Low-Voltage Applications

A wideband inductorless low-noise-amplifier (LNA) with single-to-differential conversion for multistandard radio applications is proposed. Noise-suppressed current-mirror-based biasing is utilized to ensure stable operation under process, voltage, and temperature variations. The inherent gain of the common-source (CS) stage is re-used to boost the trans-conductance of the common-gate (CG) stage, and hence, a noise- and power-efficient design is achieved without hurting the noise and distortion cancellation properties of the CG-CS-based balun topology. The gain and phase balance is improved by employing an efficient compensation scheme. The prototype was realized in 0.13- μm CMOS, operates from 0.1 to 2 GHz, and dissipates 3 mW from 1.2-V supply while occupying a 0.075-mm² active area. The balun-LNA, including the output buffer, provides 7.6-dB maximum power gain, 4.15-dB minimum noise figure, better than -10-dB input matching, and 0.5-dBm IIP₃ without any on-chip inductor.