Carlos E. Saavedra

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This paper presents a broadband low-noise mixer in CMOS 0.13-¿m technology that operates between 1-5.5 GHz. The mixer has a Gilbert cell configuration that employs broadband low-noise transconductors designed using the noise-cancelling technique used in low-noise amplifer designs. This method allows broadband input matching and without the use of inductors(More)
—A multiband flexible RF-sampling receiver aimed at software-defined radio is presented. The wideband RF sampling function is enabled by a recently proposed discrete-time mixing downconverter. This work exploits a voltage-sensing LNA preceded by a tunable LC pre-filter with one external coil to demonstrate an RF-sampling receiver with low noise figure (NF)(More)
An 8.6 GHz × 2 subharmonic mixer with complementary current-reuse to enable ultra-low-voltage and low-power operation is presented. The RF transconductance stage of the mixer uses inductive source degeneration and the mixing core uses four transistors that are driven by a quadrature LO signal. A Volterra series analysis is carried out to determine(More)
—An innovative vector-sum phase shifter with a full 360 • variable phase-shift range is proposed and experimentally demonstrated in this paper. It employs an active balun and a very high-speed CMOS operational transconductance amplifier (OTA) integrator to generate the four quadrature basis vector signals. The fabricated chip operates in the 2–3 GHz, it(More)
—A 2.4 GHz CMOS amplifier with third-order in-termodulation distortion cancellation is presented based on the derivative superposition technique. The proposed circuit uses a conventional amplifier topology followed by a distortion cancellation circuit that can significantly improve third-order linearity. To quantify the linearity improvement, two(More)
The factors that impact the intermodulation distortion performance of an active downconverting mixer are investigated. Through a Volterra-series analysis of the RF transconductor stage of the mixer, design principles are formulated to maximize the mixer's IIP<sub>3</sub>. To verify the theoretical analysis, a 0.3-1.2-GHz low-voltage mixer operating from a(More)