Broadcom Corporation

University of California

Aminghasem Safarian

Ahmadreza Rofougaran

Maryam Rofougaran

Henrik Tholstrup Jensen

Seema Butala Anand

Amin Shameli

Payam Heydari

Jianhua Gan

Lei Zhou

Shahla Khorram

Franco De Flaviis

Amir Ibrahim

Bojko Frederik Marholev

A near field RFID system includes an RFID reader and an RFID tag. The RFID reader includes a transmit path and a receive path, wherein the transmit path includes: an encoding section coupled to convert data into encoded data; a digital to analog conversion module coupled to convert the encoded data into an analog encoded signal; a power amplifier coupled to amplify the analog encoded signal; and a plurality of coils coupled to generate a plurality of electromagnetic fields from the analog encoded signal. The RFID tag that includes: a coil coupled to generate a current and a recovered signal from at least one of the plurality of electromagnetic fields; a power recovery circuit coupled to generate a voltage from the current; and a data processing section coupled to process the recovered signal, wherein the data processing section is powered via the voltage.

Near field RFID system with multiple reader coils

Techniques and devices provide analog-to-digital conversion at two or more signal frequencies or frequency hands and can be used to construct multi-mode analog-to-digital converters in various circuits, including receivers and transceivers for wireless communications and radio broadcast environments. Adjustable analog-to-digital converters based on the described techniques can be configured to adjust circuit parameters to adapt the technical specifications of different input signals at different signal frequencies or frequency bands, such as FM, HD-radio, and DAB radio signals in radio receiver applications.

Multi-mode analog-to-digital converter

Techniques and devices are disclosed to provide multi-stage gain control in circuits or devices having two or more stages of signal amplification. A circuit with multi-stage gain control can include amplification stages coupled to receive an input signal and to produce an amplified output signal. Each amplification stage includes an amplifier that is adjustable in gain and a signal detector that is coupled to measure an output signal of the amplifier and to produce a detector signal indicative of a signal strength of the output signal of the amplifier. A gain control circuit is coupled to receive detector signals from the signal detectors in the amplification stages, respectively, and to control gains of the amplifiers of the amplification stages based on respective received detector signals, respectively.

Multi-stage gain control in receivers and other circuits

A power amplifier, supplied by a supply voltage, to drive an antenna to output a magnetic field, comprising a differential stage configured to output an output signal to drive the antenna, and a feedback stage configured to receive a common mode output voltage from the differential stage and to output a feedback voltage to regulate the output common mode signal to be proportional to the supply.

Antenna driver circuit for NFC reader applications

Techniques and devices provide analog-to-digital conversion at two or more signal frequencies or frequency bands and can be used to construct multi-mode analog-to-digital converters in various circuits, including receivers and transceivers for wireless communications and radio broadcast environments. Adjustable analog-to-digital converters based on the described techniques can be configured to adjust circuit parameters to adapt the technical specifications of different input signals at different signal frequencies or frequency bands, such as FM, HD-radio, and DAB radio signals in radio receiver applications.

A novel DDCR RF front-end for use in UWB applications combining a distributed approach which provides wideband functionality of the RF front-end with I-Q requirement of DCRs. The distributed architecture uses composite cells of a merged LNA and mixer along the input RF T-line.

Distributed direct conversion receiver (DDCR) for UWB systems

A receiver architecture for canceling blocking signals in the receive path includes a low noise amplifier for receiving and amplifying an inbound RF signal to produce an amplified inbound signal, in which the inbound RF signal includes a modulated RF signal and a blocking signal, and a cancellation module for substantially canceling the blocking signal from the amplified inbound RF signal and substantially passing the modulated RF signal. The cancellation module cancels the blocking signal by generating an injection signal representative of the blocking signal, combining the blocking signal with the injection signal to produce an error signal, updating the injection signal based on the error signal and using the injection signal to cancel the blocking signal from the amplified inbound RF signal.

Integrated blocker filtering RF front end

Described herein are ultra wide-band distributed RF (UWB-DRF) front-end receivers comprising composite cells distributed along transmission lines, where each composite cell comprises a low-noise amplifier (LNA) merged with a mixer. By merging the LNA and the mixer in each composite cell, the power consumption and chip area of the RF front-end is reduced. Further, the distributed architecture of the RF front-end allows it to operate over a wide bandwidth by absorbing the parasitic capacitances of the composite cells into the transmission lines of the RF-front end. Embodiments of the RF front-end provide wideband flat gain, low noise figure (NF), wideband linearity, and wideband matching at the inputs of the RF front-end. In an embodiment, a programmable resistance at the termination of the RF transmission line allows the RF front-end to trade off a few decibels of mismatch at the RF input for higher gain and lower NF.

Growing community of inventors

Irvine, CA, United States of America

Aminghasem Safarian