Abstract:
The present disclosure relates to a radio frequency (RF) communications system, which may include any or all of RF modulation and control circuitry, RF power amplifier (PA) circuitry, a direct current (DC)-DC converter, transceiver circuitry, and front-end aggregation circuitry. Embodiments of the RF communications system may relate to reducing cost, reducing size, reducing complexity, increasing efficiency, increasing performance, the like, or any combination thereof.
Abstract:
An adaptive antenna neutralization network (AANN) for neutralizing coupling between a first antenna and a second antenna of a mobile terminal is disclosed. The AANN includes an array of reactive branches. Each of the reactive branches includes a reactive element and an electrically controlled switch with a control input for selectively coupling the reactive element between the first antenna and the second antenna. Also included is a switch driver having an output coupled to the control input of each electrically controlled switch, and a controller having an output for sending control signals to the switch driver to turn on or off individual ones of the electrically controlled switches in response to conditions that indicate a coupling state between the first antenna and the second antenna.
Abstract:
A system and method are provided for transitioning between modulation formats in adjacent transmit bursts. The system includes a modulation system having a data interface, first modulation circuitry operating according to a first modulation format, and second modulation circuitry operating according to a second modulation format. During a transition between a first transmit burst in the first modulation format and a second transmit burst in the second modulation format, the data interface receives a timing signal signifying a start of data for the second transmit burst. In response to the timing signal, the second modulation circuitry resets, and the data interface delays the data for the second transmit burst by a modulator delay time. By delaying the data for the second transmit burst, a glitch caused by resetting the second modulation circuitry arrives at the output of the second modulation circuitry prior to the data for the second transmit burst.
Abstract:
A fractional-N offset phase locked loop (FN-OPLL) is provided. The FN-OPLL includes a fractional divider, a phase detector, a loop filter, a voltage controlled oscillator (VCO), and feedback circuitry. Combiner circuitry combines an initial fractional divide value and a modulation signal to provide a combined fractional divide value. Based on the combined fractional divide value, the fractional-N divider divides a reference frequency and provides a divided reference frequency to the phase detector. The phase detector compares a phase of the divided reference frequency to a phase of a feedback signal to provide a comparison signal. The comparison signal is filtered by the loop filter to provide a control signal to the VCO, where the control signal controls a frequency of an output signal of the VCO. The output signal is processed by the feedback circuitry to provide the feedback signal to the phase detector.
Abstract:
A system and method for classifying channels in a frequency hopping wireless communication system is provided. A data collection engine operates to obtain channel metrics indicating the level of interference for each channel used by the wireless communication system. A data analysis engine operates to provide a channel map for adaptive frequency hopping (AFH) and/or a channel map for channel avoidance. More specifically, the data analysis engine first operates to filter the channel metrics to remove channel metrics indicative of frequency hopping interference. Next, the channels are divided into a number of channel blocks each including at least two adjacent channels. For each channel block, the channel metrics of the channels within the channel block are combined to provide a metric sum. The data analysis engine then operates to classify each channel as usable or unusable based on the metric sums for each of the channel blocks.
Abstract:
An RF power amplifier module can be used without a matching device between the power amplifier module and an antenna. The power amplifier module is constructed and operated to detect, protect and maintain the performance of the power amplifier in the presence of severe VSWR load mismatches, without requiring the use of external circuitry. The RF power amplifier module includes integral detection circuitry for generating a first detection signal having a value that is indicative of the current flowing through an output power transistor and a second detection signal having a value that is indicative the voltage appearing at the output of the output power transistor, as well as integral compensation circuitry for controlling the generation of a plurality of bias current and bias voltage signals to have values that are a function of the values of the first and second detection signals, as well as the current output power level of the RF power amplifier module. Also included is an integral impedance matching circuit, coupled between the output of the output transistor and the output node,. that provides a variable impedance that is selectively controlled by an output signal from the compensation circuitry.
Abstract:
The present invention relates to electrically attaching a surface mount device (10) to a mounting structure (12) via their respective contact pads (14, 16) using an attach material (28), such as solder or conductive epoxy, which includes a filler material (30). In general, the filler material is relatively solid and granular shaped, wherein the diameter of the filler material controls a mounting distance (d) between the surface mount device and the mounting structure. The filler allows a desired distance to be maintained during initial placement of the surface mount device and any subsequent reheating.
Abstract:
A DC-DC converter includes a variable frequency oscillator (36), a control system and a power train. The DC-DC converter is well suited for use in a cell phone. The control system uses the output of the oscillator to control the power train. The oscillator varies its frequency as a function of a pseudo random number generator (60), thereby reducing electromagnetic interference caused by ripple in the output of the DC-DC converter.
Abstract:
The present invention provides a method and apparatus for estimating a multipath channel with sub-chip resolution. In general, secondary signals are characterized based on correlating a received signal including multipath signals, which include a main and the secondary signals, with a pseudo-random noise code. An inverse filter operates to increase a temporal resolution of results of the correlation of the received signal and the pseudo-random noise code, thereby allowing secondary multipath signals occurring within the same chip interval as another multipath signal to be detected and estimated correctly.
Abstract:
A DC-DC converter includes a variable frequency oscillator, a control system and a power train. The DC-DC converter is well suited for use in a cell phone. The control system uses the output of the oscillator to control the power train. The oscillator varies its frequency as a function of a pseudo random number generator, thereby reducing electromagnetic interference caused by ripple in the output of the DC-DC converter.