Freescale Semiconductor,inc.

Mohammed S Alam

Daniel Lee Kaczman

Manish N Shah

Mohammed Rachedine

Lu M Han

David L Cashen

A high performance radio frequency receiver includes a low noise amplifier with large binary and stepped gain control range, controlled impedance, and enhanced blocker immunity, for amplifying and converting a radio frequency signal to a current; a pulse generator for generating in-phase and quadrature pulses; a crossover correction circuit and pulse shaper for controlling a crossover threshold of the pulses and interaction between in-phase and quadrature mixers; and a double balanced mixer for combining the RF signal with the pulses to generate an intermediate frequency or baseband zero intermediate frequency current-mode signal. The in-phase and quadrature pulses have a duty cycle of 20-35%. The intermediate frequency signal and second order harmonics may be filtered with a high frequency low pass filter and a current injected complex direct-coupled filter. Decreased die size, current drain, cost, and complexity, as well as improvements in gain, 1/f noise, noise figure, sensitivity, and linearity may result.

High performance CMOS radio frequency receiver

A multi-band high gain mixer and quadrature signal generator allows a receiver system to receive signals at multiple frequency bands without requiring significant hardware duplication. A single mixer directly receives any of three communication frequency bands such as Universal Mobile Telecommunication System (UMTS), Personal Communication Services (PCS), Digital Communication System (DCS), and Japan and US W-CDMA 800 bands without amplification. A Serial-Parallel Interface selectably forwards RF signals within the receiver's frequency channels to the mixer for demodulation into in-phase (I) and quadrature (Q) signals at a common IF output from the multi-mode receiver. Significant power and cost advantages are attained by elimination of duplicate mixers and amplifier stages.

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Grayslake, IL, United States of America

Mohammed S Alam