International Business Machines Corporation

Tahoe Rf Semiconductor, Inc.

Other

Darrell Lee Livezey

Joy Laskar

Jonathan Lee Kennedy

Michael Joseph Shaw

Robert S Moore

Lewis John Harthan, Iii

A method includes providing a highly linear front end in a Radio Frequency (RF) receiver, implementing a high Effective Number of Bits (ENOB) Analog to Digital Converter (ADC) circuit in the RF receiver, and sampling, through the high ENOB ADC circuit, at a frequency having harmonics that do not coincide with a desired signal component of an input signal of the RF receiver to eliminate spurs within a data bandwidth of the RF receiver. The input signal includes the desired signal component and an interference signal component. The interference signal component has a higher power level than the desired signal component. The method also includes simultaneously accommodating the desired signal component and the interference signal component in the RF receiver based on an increased dynamic range of the RF receiver and the high ENOB ADC circuit provided through the highly linear front end and the high ENOB ADC circuit.

Simultaneous accommodation of a low power signal and an interfering signal in a radio frequency (RF) receiver

A transconductance comparator includes a comparator having an output of a detector configured to sense an amplitude of an output of a Variable Gain Amplifier (VGA) of a receiver as a first input and a reference amplitude level as a second input. The comparator generates an error signal based on the first input and the second input. The transconductance comparator also includes a transconductance amplifier having a differential voltage input based on the error signal generated through the comparator and generating an output current. The transconductance amplifier includes current sources associated with programmable current limits thereof and differential pairs associated with the current sources, one or more of which is implemented with a size mismatch between transistors thereof to eliminate an offset error due to a mismatch between the current limits, thereby enabling programmability of an attack time and a decay time during automatic gain control of the VGA.

Automatic gain control with programmable attack and decay times

A phase-locked loop circuit includes one loop for regulating phase of a VCO with respect to a reference source. In another loop, VCO frequency is compared to frequency of a crystal oscilator. Digital counters divide the frequency of the crystal oscillator and VCO to a common reference frequency. Once the frequency loop is locked, the counter at the output of the crystal oscillator is bypassed. The counter is bypassed by a flip-flop circuit clocked by the crystal oscillator and receiving a scaled input from the VCO. While the VCO frequency error is in the frequency range of correction capability of the Phase-locked loop, the output of the flip-flop will duplicate the output of the counter. Thus, the counter can be bypassed and shut off.

Phase-locked loop oscillator with counter bypass

A technique controls a charge pump bias circuit in a phase-locked loop (PLL) circuit. The charge pump bias circuit biases a charge pump circuit. A digital phase detector generates direction control signals based on reference and pre-scale count signals from reference and pre-scale counting circuits, respectively. The direction control signals control direction of current pumped by the charge pump circuit. A charge pump enable generator generates an enable signal based on look-ahead reference and pre-scale count signals from the reference and pre-scale counting circuits, respectively. The look-ahead reference and pre-scale count signals are generated before the corresponding reference and pre-scale count signals by a predetermined time interval. The enable signal powers down the charge pump bias circuit after the charge pump circuit pumps the current.

Look-ahead enabling charge pump in phase-locked loop circuits

A system for producing realistic tactile feedback forces in a tool operation simulator. Sensors sense the location and direction of movement of a simulated tool in a simulated landscape environment to produce electrical signals representing three dimensional location and direction of movement. These electrical signals are processed by re-programmable processors to produce control signals that are fed to pneumatic bi-directional piston-type actuators to impart realistic forces similar to forces that would be encountered in corresponding real-life movement of the simulated tool.

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Auburn, CA, United States of America

Darrell Lee Livezey