Silicon Laboratories Inc.

Other

Nxp B.v.

St-ericsson Sa

James P Maligeorgos

Augusto Manuel Marques

Donald A Kerth

Lysander Lim

G Tyson Tuttle

Jeffrey William Scott

Richard T Behrens

Aslamali A Rafi

Caiyi Wang

Gregory Takeo Uehara

Vishnu Shankar Srinivasan

G Diwakar Vishakhadatta

Dylan Alexander Hester

Tod Paulus

Russell Croman

Brian Douglas Green

Xiaochuan Guo

Xiachuan Guo

Brian Green

A technique includes generating an analog voltage to control a frequency for an oscillator. The analog signal is converted into a digital signal, and the frequency is controlled in response to the digital signal.

Controlling the frequency of an oscillator

A wireless communication device is disclosed wherein isolation buffers couple to respective active circuits or stages of the device to convey test information regarding such active circuits to a test data line from which status information may be collected. The communication device operates in two modes, namely a normal operational mode wherein the isolation buffers effectively short spurious emissions from the active circuits to a ground, and a test mode wherein the isolation buffers may convey test information from a selected active circuit to the test data line. The isolation buffers prevent spurious emissions from escaping the active circuits to which they are coupled and prevent spurious emissions from traveling from active circuit to active circuit over the test data line throughout the wireless device.

System and method for reducing spurious emissions in a wireless communication device including a testing apparatus

A technique includes selectively coupling impedances to an oscillator to establish a first frequency of operation of the oscillator. The technique includes repeating the selective coupling in a feedback loop to cause the first frequency to be near a second frequency.

A voltage regulator configured to receive a supply voltage from a voltage supply and provide a regulated voltage to digital circuitry is provided. The voltage regulator comprises first circuitry configured to inhibit high frequency energy generated by the digital circuitry from transmitting into the voltage supply, second circuitry configured to inhibit low frequency energy generated by the digital circuitry from transmitting into the voltage supply, and third circuitry configured to maintain the regulated voltage at a substantially constant value in response to a current drawn by the digital circuitry.

Voltage regulator with shunt feedback

In one embodiment, the present invention includes a capacitor array that may provide a selected capacitance to a digitally controlled crystal oscillator (DCXO). The array may include multiple sections each having at least one array portion, where each section is to receive different significant portions of a digital control value. The different sections may have different coding schemes. Other embodiments are described and claimed.

Capacitor array segmentation

Components of a radio-frequency (RF) apparatus including transceiver circuitry and frequency modification circuitry of a crystal oscillator circuit that generates a reference signal with adjustable frequency may be partitioned in a variety of ways, for example, as one or more separate integrated circuits. The frequency modification circuitry may be implemented as part of a crystal oscillator circuit that includes digitally controlled crystal oscillator ('DCXO') circuitry and a crystal. The frequency modification circuitry may include at least one variable capacitance device and may be employed to generate a reference signal with adjustable frequency. The adjustable reference signal may be provided to other components of the RF apparatus and/or the RF apparatus may be configured to provide the adjustable reference signal to baseband processor circuitry. Automatic frequency control (AFC) circuitry may be integrated with other components of RF circuitry and may generate frequency control signals for the frequency modification circuitry based on, for example, a signal received from a temperature sensor. Digital-to-analog converter (DAC) circuitry may be integrated with other components of RF circuitry to enable all-digital frequency control communications from baseband processor circuitry to RF circuitry.

Partitioning of radio-frequency apparatus

Frequency modification circuitry may be employed as part of a crystal oscillator circuit to generate a reference signal with adjustable frequency. The frequency modification circuitry may be implemented as part of a crystal oscillator circuit that includes digitally controlled crystal oscillator ('DCXO') circuitry and a crystal. The frequency modification circuitry may adjust the frequency of the reference signal in response to one or more frequency control signals. In one example, the frequency modification circuitry may include variable capacitors such as one or more continuously variable and/or discretely variable capacitors for providing coarse and/or fine adjustment of the reference signal frequency.

Frequency modification circuitry for use in radio-frequency communication apparatus and associated methods

Systems and methods for providing an adjustable reference signal to RF circuitry

A frequency multiplication circuit is disclosed. The circuit includes a ring oscillator formed of an even number of phase shifting stages. Each phase shifting stage provides a high frequency output comprised of harmonics of the oscillation frequency of the oscillator. An input signal having a first frequency is injected into a feedback node of the oscillator, thereby injection locking the oscillator to the input signal such that the oscillation frequency of the oscillator is equal to the first frequency. An output signal is extracted from two of the phase shifting stages. One of the harmonic frequencies may be isolated in the output signal, thereby providing a clean output at a multiple of the input frequency. When the circuit is operated at high frequencies, the output signal consists substantially of the second harmonic frequency and the circuit operates as a frequency doubler. A pair of frequency doublers may be cascaded to form a frequency quadrupler capable of providing an output signal with a frequency greater than 10 GHz.

Growing community of inventors

Austin, TX, United States of America

James P Maligeorgos