Psemi Corporation

Murata Manufacturing Co., Ltd.

Joseph Golat

David Kovac

Methods and apparatuses for controlling gain of a single stage cascode FET amplifier are presented. According to one aspect, a series-connected resistor and capacitor is coupled to a gate of a cascode FET transistor of the amplifier, the capacitor providing a short at frequencies of operation of the amplifier. According to another aspect, values of the resistor can be used to control gain of the amplifier. According to yet another aspect, the resistor is a variable resistor whose value can be controlled/adjusted to provide different gains of the amplifier according to a linear function of the resistor value. An input matching network coupled to an input of the amplifier can be used to compensate for different noise figure degradations from different values of the resistor.

Cascode gain boosting and linear gain control using gate resistor

Methods and devices for reducing coupling of RF frequency components between different bands of an RF system are presented. According to one aspect, a notch filter having a notch centered at a harmonic of a fundamental frequency of a first band transmit side is coupled to an output of an LNA of the first band. According to another aspect, the harmonic is a second harmonic, a third harmonic or higher order harmonics. According to another aspect, the notch filter includes a plurality of notches at respective plurality of harmonics. According to a further aspect, the notch has an attenuation of 30 dB or greater at the second harmonic and 10 dB or greater at the third harmonic. Further included is a method for reducing coupling of harmonics of signals transmitted in the first band into a receive path of the second band, thereby increasing noise figure/sensitivity performances of the receive path.

LNA with Tx harmonic filter

A receiver front end capable of receiving and processing intraband non-contiguous carrier aggregate (CA) signals using multiple low noise amplifiers (LNAs). Cascode circuits, each having a 'common source' configured input FET and a “common gate” configured output FET, serve as the LNAs. An amplifier-branch control switch, configured to withstand relatively high voltage differentials by means of a relatively thick gate oxide layer and coupled between a terminal of the output FET and a power supply, controls the ON and OFF state of each LNA while enabling use of a relatively thin gate oxide layer for the output FETs, thus improving LNA performance. Some embodiments may include a split cascode amplifier and/or a power amplifier.

Source switch split LNA design with thin cascodes and high supply voltage

Methods and apparatuses for providing a tunable Wilkinson power splitter are presented. According to one aspect, the tunable splitter includes tunable branches realized via lumped elements that provide controlled impedance and phase at different selectable center frequencies of operation. For each of the center frequencies, the tunable Wilkinson splitter has a performance according to a corresponding fixed center frequency Wilkinson power splitter provided by a relatively narrow instantaneous bandwidth. Over a number of the center frequencies supported, performances of the tunable Wilkinson splitter overlap to provide a combined performance having a desired wider bandwidth. According to another aspect, each of the tunable branches includes an LC network that includes tunable capacitors and inductors. One or more of the tunable Wilkinson power splitters can be cascaded to provide a performance according to a wider instantaneous bandwidth.

Tunable Wilkinson splitter

Methods and devices used to cancel non-linear capacitances in high power radio frequency (RF) switches manufactured in bulk complementary metal-oxide-semiconductor (CMOS) processes are disclosed. The methods and devices are also applicable to stacked switches and RF switches fabricated in silicon-on-insulator (SOI) technology.

Growing community of inventors

Crystal Lake, IL, United States of America

Joseph Golat