Qorvo US, Inc.

Apple Inc.

National Semiconductor Corporation

Hideya Oshima

George Adrian Maxim

Baker P Scott

Dirk Robert Walter Leipold

Daniel Charles Kerr

Eric K Bolton

Jinsung Choi

Richard Dean Henderson

Abbas Komijani

Hongrui Wang

Mehmet Aslan

Reetika Kumari Agarwal

Chungwai Benedict Ng

Qing Feng Ren

Michael Wong

In a charge pump-based PLL circuit, charge pump output current variation may cause phase instability at an output of a VCO. The output current variation may be caused by low-frequency disturbances (e.g., tuning voltage (Vtune) drift with channel length modulation effect), disturbance in a gate bias voltage of a transistor, or a VDD transient. Such a low-frequency disturbance may occur during initial lock, which may affect phase settling time, or after lock, which may result in phase instability. A replica charge pump and a current filtering and compensation circuit may be implemented at the output of a main charge pump to provide error current compensation to suppress channel length modulation effect, improve phase stability, and reduce phase noise.

Systems and methods for improved charge pump phase-locked loop phase stability

A radio frequency switch having an N number of switch cells coupled in series is disclosed. Each of the switch cells includes a field-effect transistor (FET), wherein a source of switch cellis coupled to a first port, a drain of switch cell N is coupled to a second port, and a drain of switch cell X is coupled to a source of switch cell X+1 for switch cellthrough switch cell N. A first diode stack has a first anode coupled to the body of switch cell X and a first cathode coupled to a drain of switch cell X+1 for switch cellthrough switch cell N&#x2212;1, and a second diode stack has a second anode coupled to the body of switch cell X and a second cathode coupled to the source of switch cell X&#x2212;1 for switch cellthrough switch cell N.

Radio frequency switch

A power amplifier system is disclosed. The power amplifier system includes a power amplifier having a first signal input and a first signal output and a main bias circuitry configured to provide a first portion of a first bias signal to the power amplifier through a first bias output coupled to the first signal input. Further included is peak bias circuitry that is configured to provide a second portion of the first bias signal to the power amplifier through a second bias output coupled to the first signal input, wherein the first portion of the first bias signal is greater than the second portion of the first bias signal over a first input power range and the second portion of the first bias signal is greater than the first portion of the first bias signal over a second input power range that is greater than the first input power range.

Power amplifier system

A transistor-based radio frequency (RF) switch that provides symmetric RF impedance is disclosed. The transistor-based RF switch includes an N number of main field-effect transistors (FETs) stacked in series between a first end node and a second end node. A first end-network is coupled between the first end node and a proximal gate node. The first end-network provides a first variable impedance that equalizes a drain-to-source voltage of the first main FET to within a predetermined percentage of a drain-to-source voltage of a second main FET of the N number of main FETs. A second end-network is coupled between the second end node and the distal gate node, wherein the second end-network provides a second variable impedance to equalize the drain-to-source voltage of an Nth main FET to within the predetermined percentage of the drain-to-source voltage of an N&#x2212;1 main FET of the N number of main FETs.

Transistor-based radio frequency (RF) switch

Improved Radio Frequency (RF) switches are provided herein. According to one aspect, an RF switch comprises one or more stages. In one embodiment, each stage comprises a signal input terminal, a signal output terminal, a control input terminal, and a switching device having a first terminal connected to the signal input terminal, a second terminal connected to the signal output terminal, and a third terminal for controlling the on/off state of the switching device. Each stage includes a first resistor connected in series between the control input terminal and the third terminal, a first bypass switch for electrically bypassing the first resistor, and a second resistor connected in series between the signal input terminal and the signal output terminal. The first resistors form a first bias network, the second resistors form a second bias network, and the switching devices are connected in series.

RF branch with accelerated turn-on and high Q value

Disclosed is a transistor-based switch having an N number of main field-effect transistors (FETs) stacked in series such that a first terminal of a first main FET of the N number of main FETs is coupled to a first end node and a second terminal of an Nth main FET of the N number of main FETs is coupled to a second end node, wherein N is a finite number greater than five. The transistor-based switch further includes a gate bias network having a plurality of gate resistors, wherein individual ones of the plurality of gate resistors are coupled to gate terminals of the N number of main FETs. A common gate resistor is coupled between a gate control input and a gate control node of the plurality of gate resistors, and a capacitor is coupled between the gate control node and a switch path node of the main FETs.

A Radio Frequency (RF) switch having two or more stages coupled in series is disclosed. A first Field-Effect Transistor (FET) with a first control terminal is coupled across a gate resistor to shunt the gate resistor when the first FET is on. An RF switching device is configured to pass an RF signal between a signal input and a signal output when the RF switching device is on. A second FET having a second control terminal coupled to an acceleration output is configured to shunt the RF switching device when the second FET is on. A third FET is coupled between the first control terminal and the signal input for controlling charge on a gate of the first FET. A third control terminal of the third FET is coupled to an acceleration input for controlling an on/off state of the third FET.

Radio frequency (RF) switch with on and off switching acceleration

A method and apparatus improves the accuracy of temperature measurements by sampling measurements from a remote sensor, where currents of different current densities are applied to the remote sensor in a time-interleaved fashion. The remote sensor includes at least one PN junction that produces a voltage corresponding to the applied current at each instance of time, and related to the temperature of the remote sensor. By applying time-interleaved current densities to the remote sensor, adverse effects from temperature variations during the measurement are minimized. Sequences of current biases having differing current densities in a forward order are applied to the remote sensor, followed by the same sequence being applied to the remote sensor in a reverse order. Similarly, a random or pseudo-random sequence may be employed in a forward and reverse order. The application of forward and reverse sequences is utilized to minimize errors in the temperature measurement.

Growing community of inventors

Santa Clara, CA, United States of America

Hideya Oshima