Patent application number | Description | Published |
20090102562 | CROSS-COUPLED LOW NOISE AMPLIFIER FOR CELLULAR APPLICATIONS - Cross-coupled low noise amplifier for cellular applications. A circuitry implementation that includes two pairs of metal oxide semiconductor field-effect transistors (MOSFETs) (either N-type of P-type) operates as an LNA, which can be used within any of a wide variety of communication devices. In one embodiment, this design is particularly adaptable to cellular telephone applications. A majority of the elements are integrated within the design and need not be implemented off-chip, and this can provide for a reduction in area required by the circuitry. A very high output impedance is provided by using two transistors (implemented in a triple well configuration) with resistive source degeneration. A higher than typical power supply voltage can be employed (if desired) to accommodate the voltage drops of the resistors and transistors. | 04-23-2009 |
20090104873 | FULLY INTEGRATED COMPACT CROSS-COUPLED LOW NOISE AMPLIFIER - Fully integrated compact cross-coupled low noise amplifier. A circuitry implementation that includes two pairs of metal oxide semiconductor field-effect transistors (MOSFETs) (either N-type of P-type) operates as an LNA, which can be used within any of a wide variety of communication devices. A majority of the elements are integrated within the design and need not be implemented off-chip, and this can provide for a reduction in area required by the circuitry. A differential 100Ω input impedance is provided by this design. A higher than typical power supply voltage can be employed (if desired) to accommodate one possible implementation that includes two parallel implemented resistors to ground. | 04-23-2009 |
20090134932 | LOW FLICKER NOISE MIXER AND BUFFER - Low flicker noise mixer and buffer. This design employs some native metal oxide semiconductor field-effect transistors (MOSFETs) (e.g., having no threshold voltage) within a passive mixer whose gates are driven using clock signals. These native MOSFETs maybe biased at one half of the power supply voltage to provide a lower noise figure. A cooperatively operating buffer employs appropriately places MOSFETs and resistors to ensure the desired gain. Relatively larger valued resistors can be employed to provide for higher voltage gain, and this can sometimes be accompanied with using a higher than typical power supply voltage. Source followers serve as output buffers and also ensure the required output DC voltage level as well. It is also noted that this design can be implemented using n-channel metal oxide semiconductor field-effect transistors (N-MOSFETs) of p-channel metal oxide semiconductor field-effect transistors (P-MOSFETs). | 05-28-2009 |
20090134942 | RADIO FREQUENCY AMPLIFIER WITH CONSTANT GAIN SETTING - Radio frequency amplifier with constant gain setting. A circuitry that includes triple well connected MOSFETs is employed to eliminate body effects therein. The voltage gain as presented herein, being implemented using a ratio of certain elements within the circuitry, is immune to variations in temperature, power supply voltage, and process variations. One implementation employs an array of selectable MOSFETs to allow for more than one gain setting to be provided by the amplifier. Such an amplifier has a variable/selectable gain setting. An appropriately placed MOSFET is employed to provide the desired input impedance (e.g., 50Ω). This design can be implemented using multiple n-channel metal oxide semiconductor field-effect transistors (N-MOSFETs) (some of which are triple well connected) and p-channel metal oxide semiconductor field-effect transistors (P-MOSFETs), or alternatively using P-MOSFETs and N-MOSFETs. | 05-28-2009 |
20090237165 | Cross-coupled low noise amplifier for cellular applications - Cross-coupled low noise amplifier for cellular applications. A circuitry implementation that includes two pairs of metal oxide semiconductor field-effect transistors (MOSFETs) (either N-type of P-type) operates as an LNA, which can be used within any of a wide variety of communication devices. In one embodiment, this design is particularly adaptable to cellular telephone applications. A majority of the elements are integrated within the design and need not be implemented off-chip, and this can provide for a reduction in area required by the circuitry. A very high output impedance is provided by using two transistors (implemented in a triple well configuration) with resistive source degeneration. A higher than typical power supply voltage can be employed (if desired) to accommodate the voltage drops of the resistors and transistors. | 09-24-2009 |
20100026402 | Low phase noise differential crystal oscillator circuit - A differential crystal oscillator circuit uses a bias transistor to generate a bias voltage from a bias current. The bias voltage is supplied to the control terminals of a differential pair of transistors. The differential transistors operate to produce a differential output between corresponding end terminals thereof, which is provided to a reference crystal oscillator to establish an oscillation frequency at the differential output. | 02-04-2010 |
20100039194 | Monotonic frequency tuning technique for DCXO in cellular applications - A frequency tuning device for use in a crystal oscillator circuit includes a first fine tuning array of capacitors, a second fine tuning array of capacitors and a coarse tuning array of capacitors coupled in parallel to produce a tuning capacitance for tuning the crystal oscillator. The first fine tuning array of capacitors includes a binary weighted switched capacitor network, the second fine tuning array of capacitors includes a thermometer coded switched capacitor network and the coarse tuning array of capacitors includes a binary weighted switched capacitor network with a different unit capacitance value than the first and second fine tuning arrays. | 02-18-2010 |
20100317311 | Protection for SAW-Less Receivers - Embodiments of a SAW-less RF receiver front-end that includes a frequency translated notch filter (FTNF) are presented. An FTNF includes a passive mixer and a baseband impedance. The baseband impedance includes capacitors that form a low-Q band-stop filter. The passive mixer is configured to translate the baseband impedance to a higher frequency. The translated baseband impedance forms a high-Q notch filter and is presented at the input of the FTNF. The FTNF can be fully integrated in CMOS IC technology (or others, e.g., Bipolar, BiCMOS, and SiGe) and applied in wireless receiver systems including GSM, EDGE, Wideband Code Division Multiple Access (WCDMA), Bluetooth, and wireless LANs (e.g., IEEE 802.11). In addition, embodiments of an apparatus to protect SAW-less RF receiver front-ends are presented. | 12-16-2010 |
20110002257 | Method and system for processing signals in a high performance receive chain - Aspects of a method and system for processing signals in a high performance receive chain may include amplifying a plurality of radio frequency signals in one or more respective one or ones of a plurality of amplifier chains in a multistandard radio frequency front-end, which may comprise one or more shared processing stages. The plurality of radio frequency signals may be compliant with a plurality of radio frequency communication standards and may be received concurrently. The one or more shared processing stages may be shared between two or more of the plurality of amplifier chains. Each of the two or more of the plurality of amplifier chains may be operable to amplify signals compliant with different radio frequency communication standards. | 01-06-2011 |
20110003574 | Constant Output DC Bias Circuit Using an Open Loop Scheme - Embodiments of the present invention provide constant output DC biasing circuits. Embodiments employ an open loop scheme, instead of a closed loop scheme as used in conventional circuits. In addition, embodiments generate a DC bias voltage that is independent of temperature, process, and power supply variations. Further, embodiments require low amounts of power and silicon. | 01-06-2011 |
20110018604 | Configurable Clock Signal Generator - A method to provide a low-power clock signal or a low-noise clock signal is described herein. It is determined whether a low-power mode or a low-noise mode is in use. A voltage reference input of a low-dropout voltage regulator (LDO) is switched to a low-power voltage reference for low-power mode and to a low-noise voltage reference for low-noise mode. The LDO provides a constant voltage output to a crystal oscillator. A clock signal is generated using the crystal oscillator. The clock signal is limited using a low-power limiter to generate a low-power output clock signal and/or is limited using a low-noise limiter to generate a low-noise clock signal. The low-power output clock signal or the low-noise output clock signal is selected using a mux. | 01-27-2011 |
20110143822 | FULLY INTEGRATED COMPACT CROSS-COUPLED LOW NOISE AMPLIFIER - Fully integrated compact cross-coupled low noise amplifier. A circuitry implementation that includes two pairs of metal oxide semiconductor field-effect transistors (MOSFETs) (either N-type of P-type) operates as an LNA, which can be used within any of a wide variety of communication devices. A majority of the elements are integrated within the design and need not be implemented off-chip, and this can provide for a reduction in area required by the circuitry. A differential 100Ω input impedance is provided by this design. A higher than typical power supply voltage can be employed (if desired) to accommodate one possible implementation that includes two parallel implemented resistors to ground. | 06-16-2011 |
20110306311 | Adaptively powered local oscillator generator circuit and related method - According to one embodiment, a radio frequency (RF) transceiver includes a local oscillator generator (LOGEN) circuit configured to receive an adaptive supply voltage. The LOGEN circuit is coupled to a variable power supply for providing the adaptive supply voltage. A process monitor for the LOGEN circuit is in communication with the variable power supply through a power supply programming module. As a result, the adaptive supply voltage can be adjusted according to data supplied by the process monitor. A method for adaptively powering a LOGEN circuit comprises providing power to an RF device, monitoring a process corner of said LOGEN circuit, determining a supply voltage corresponding to the process corner, and adjusting the supply voltage to adaptively power the LOGEN circuit. | 12-15-2011 |
20120068780 | Systems and Methods for Reducing Frequency Pulling in an Oscillator Circuit - Methods and systems are provided to calibrate an oscillator circuit to reduce frequency pulling as a result of a change in power to a portion of the oscillator circuit. In an embodiment, an oscillator is coupled to a clock buffer circuit and a tuning capacitor configured to tune a frequency of the oscillator to a baseline frequency required for cellular communications. A change in power to the clock buffer circuit initiates a change in an amount of capacitance seen by the oscillator, which negatively impacts the tuning of the oscillator. A register stores a frequency offset caused by the change in power, and the tuning capacitor is adjusted, using the frequency offset, in response to the change in power, such that the total amount of capacitance seen by the oscillator is not changed when the change in power occurs. | 03-22-2012 |
20120329417 | Low Noise Amplifier Protection Using A Peak Detector - Embodiments of a radio frequency (RF) receiver implementing one or more forms of protection to protect devices of the RF receiver from in-band interferers is provided. The RF receiver includes an integrated circuit terminal configured to couple a RF signal received at an antenna to a RF signal path, and a low noise amplifier (LNA) coupled to the RF signal path and configured to amplify the RF signal to provide an amplified RF signal. To protect the LNA from in-band interferers, the RF receiver can further include one or more clamping circuits and/or an over-voltage detector to determine if a peak of the RF signal exceeds an acceptable level. | 12-27-2012 |
20120329418 | LOW NOISE AMPLIFIER PROTECTION USING A CLAMPING DEVICE - Embodiments of a radio frequency (RF) receiver implementing one or more forms of protection to protect devices of the RF receiver from in-band interferers is provided. The RF receiver includes an integrated circuit terminal configured to couple a RF signal received at an antenna to a RF signal path, and a low noise amplifier (LNA) coupled to the RF signal path and configured to amplify the RF signal to provide an amplified RF signal. To protect the LNA from in-band interferers, the RF receiver can further include one or more clamping circuits and/or an over-voltage detector to determine if a peak of the RF signal exceeds an acceptable level. | 12-27-2012 |
20130127555 | Systems and Methods for Reducing Frequency Pulling in an Oscillator Circuit - Methods and systems are provided to calibrate an oscillator circuit to reduce frequency pulling as a result of a change in power to a portion of the oscillator circuit. In an embodiment, an oscillator is coupled to a clock buffer circuit and a tuning capacitor configured to tune a frequency of the oscillator to a baseline frequency required for cellular communications. A change in power to the clock buffer circuit initiates a change in an amount of capacitance seen by the oscillator, which negatively impacts the tuning of the oscillator. A register stores a frequency offset caused by the change in power, and the tuning capacitor is adjusted, using the frequency offset, in response to the change in power, such that the total amount of capacitance seen by the oscillator is not changed when the change in power occurs. | 05-23-2013 |
20130157603 | METHOD AND SYSTEM FOR PROCESSING SIGNALS IN A HIGH PERFORMANCE RECEIVE CHAIN - Aspects of a method and system for processing signals in a high performance receive chain may include amplifying a plurality of radio frequency signals in one or more respective one or ones of a plurality of amplifier chains in a multistandard radio frequency front-end, which may comprise one or more shared processing stages. The plurality of radio frequency signals may be compliant with a plurality of radio frequency communication standards and may be received concurrently. The one or more shared processing stages may be shared between two or more of the plurality of amplifier chains. Each of the two or more of the plurality of amplifier chains may be operable to amplify signals compliant with different radio frequency communication standards. | 06-20-2013 |