Freescale Semiconductor,inc.

Motorola Corporation

Yan Cui

Jyoti P Mondal

Lawrence Edwin Connell

Poojan Wagh

Patrick Lee Rakers

Joseph P Golat

Neil Calanca

A transmitter includes a modulating and combining circuit to which signals are supplied and modulated into in-phase and quadrature-phase signals. The in-phase and quadrature-phase signals are combined in a closed-loop voltage summing circuit. The voltage summing circuit is an amplifier using capacitors as negative feedback elements. The negative feedback improves the linearity of the modulator. An LC tank circuit at the output of the voltage summing circuit bandpass filters the output before being applied to a power amplifier and eventually transmitted by an antenna. A multi-summing amplifier with different frequency tuning can be used for a multi-band transmitter design.

Phase modulating and combining circuit

Method and apparatus are provided for high linearity and low noise communication signal mixing. The apparatus includes a high linearity low noise mixer having an input stage coupled to a switch stage by a series-coupled blocking capacitance and input resistance. The input stage includes a buffer with negative feedback, and the switch stage includes a transistor based switch network connected to an amplifier that has feedback resistance and shunting capacitance. The method includes AC coupling an RF signal, increasing a gain of the RF signal, reducing third-order distortion by negatively feeding-back the RF signal, blocking IM2 generated from said gain increasing step, increasing a second-order input intercept point (IIP2) by attenuating the RF signal across a resistance, and applying a local oscillator input to the RF signal.

High linearity and low noise CMOS mixer and signal mixing method

In a particular embodiment, an oscillator adjustment circuit is disclosed. The oscillator adjustment circuit includes a resonator portion comprising a capacitive element coupled to an inductive element and a signal balancing portion comprising a secondary coil of the transformer. The inductive element comprises a primary coil of a transformer. The secondary coil has a grounded center tap.

Transformer coupled oscillator and method

A method for operating a wide band voltage controlled oscillator comprises using a control voltage to tune the capacitance of at least one hybrid n&plus; and p&plus; gate-doped voltage variable capacitor of the wide band voltage controlled oscillator. A hybrid voltage variable capacitor includes a substrate, a well adjacent to the substrate, a first and second set of contact elements adjacent to the well, a first channel layer adjacent to the well and bound by the first set of contact elements, a first insulating layer adjacent to the first channel layer, a first electrode adjacent to the first insulating layer, a second channel layer adjacent to the well and bound by the second set of contact elements, a second insulating layer adjacent to the second channel layer, and a second electrode adjacent to the second insulating layer.

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Gurnee, IL, United States of America

Yan Cui