Entropic Communications, Inc.

Rf Magic, Inc.

Uniden San Diego Research & Development Center, Inc.

Uniden America Corporation

Uniden Financial, Inc.

Martin Alderton

Biagio Bisanti

Stefano Cipriani

Francesco Coppola

Lorenzo Carpineto

Gianni Puccio

Eric Duvivier

Branislav A Petrovic

Jeremy Mark Goldblatt

Wing Fat Lau

Peter J Shah

YongSik Youn

Francesco Villa Lilly Coppola

Stefano Res Monteverdi Cipriani

Eric Res Monceau Bat A1 Duvivier

Biagio Les Terrasses D'antibes Bat 1E Bisanti

Various embodiments implement apparatuses and methods for conversion of radio frequency (RF) signals to intermediate frequency (IF) signals. More particularly, some embodiments are directed toward down conversion of RF signals to IF signals in a multi-band radio receiver, such as a satellite receiver, using a single oscillator for different frequency bands. For example, some of the apparatuses and methods presented are suitable for integration into monolithic RF integrated circuits in low-cost satellite receivers for home entertainment use.

Apparatuses and methods for conversion of radio frequency (RF) signals to intermediate frequency (IF) signals

Various embodiments implement waveguides for signal distribution or signal filtering in satellite receivers. According to some embodiments, a low noise block downconverter (LNB) is implemented using waveguides configured for signal distribution, band pass filtering, low pass filtering, high pass filtering, or band stop filtering. For some embodiments, the waveguides may be formed by the LNB chassis and the ground plane of a printed circuit board mounted to the LNB chassis.

Signal distribution and filtering in low noise block downconverters

A tuner uses a bank of tracking filters to preselect a channel to be received. Each tracking filter covers a range of frequencies. The tracking filters are tunable in frequency using switched capacitors and are tunable in gain by using switched resistors. The switched resistors can be controlled by an automatic gain control circuit that monitors the selected signal and adjust the tracking filter gain to achieve a desired signal level. A switch directs the received signal or signal from a test tone generator into the tracking filters. The test tone, generated by a frequency agile circuit, can be used to calibrate the filters, both in frequency and gain.

Tracking filter for tuner

A tunable multiple frequency source system employing offset signal phasing includes a first frequency source, a phase delay element, and a second frequency source configured to operate concurrently with the first frequency source. The first frequency source includes an input coupled to receive a reference input signal and an output for providing a first frequency source signal. The phase delay includes an input coupled to receive the input reference signal, and an output, the phase delay element operable to apply a predefined phase delay to the input reference signal to produce a phase-delayed input signal. The second frequency source includes an input coupled to receive the phase-delayed input signal and an output for providing a second frequency source signal.

Offset signal phasing for a multiple frequency source system

A multiple frequency source system includes at least one frequency source tunable to a predefined target frequency, and at least one additional frequency source operable to generate a second signal at a frequency which is either higher or lower than the target frequency. A method for tuning the tunable frequency source to the target frequency during concurrent generation of the second signal includes (i) controlling the tunable frequency source to tune to at least one frequency point frequency lower than the target frequency, and thereafter controlling the oscillator to tune to the target frequency, when the second signal is higher in frequency than the target frequency, or (ii) controlling the tunable frequency source to tune to at least one frequency point higher than the target frequency, and thereafter controlling the tunable frequency source to tune to the target frequency, when the second signal is lower in frequency than the target frequency.

Multiple frequency source system and method of operation

A method for mitigating phase pulling in multiple frequency source system includes generating a first signal, the first signal referred to as an existing signal operating at an existing frequency point, the existing signal having a predefined pulling bandwidth around the existing frequency point. A request is received to generate a prospective signal at a prospective frequency point which is within the predefined pulling bandwidth of the existing signal. The prospective frequency is removed from within the predefined pulling bandwidth, and the prospective and existing signals are generated at the corresponding frequency points.

System and method for mitigating phase pulling in a multiple frequency source system

A system for extracting and compensating for reference frequency error adapted for use with a communication system. The system includes a frequency generator for outputting a reference signal of a first frequency. The frequency generator has acontrol input for adjusting the first frequency in response to a control signal. A receive circuit receives an input signal and provides an output signal having a first and second component in response thereto. An error extraction circuit provides an error value based on a phase difference between the first component and the second component, and provides the control signal in response thereto. The error extraction circuit preferably includes a positive error counting circuit for generating a positive count when the first component lags the second component and a negative error counting circuit for generating a negative count when the first component leads the second component. A frequency error control circuit generates the control signal from the difference of the positive count and the negative counts.

System and method for extracting and compensating for reference frequency error in a communications system

Methods and apparatus for performing DC&mdash;DC converter synchronization in a mobile DC-powered device in which the variable clock output of a serial communications circuit is utilized to synchronize the clock which provides the switching function in the DC&mdash;DC converter.

Methods and apparatus for DC-DC converter synchronization in a mobile DC-powered device

A shunt feedback circuit path for use in high frequency amplifiers fabricated as a transmission line coupled to ground at one end and coupled to the shunt feedback transmission line of the amplifier at the other end. The shunt feedback transmission line has a first and second resistive element and a first and second capacitive element. A quarter-wavelength transmission line is used to transform the impedance coupled to one end with respect to the other end. The impedance as seen from one end of the line is a function of the characteristic impedance of the line. Therefore, by selecting the characteristic impedance the transmission line can be used to affect the impedance of the feedback path so the transmission line appears as an inductor of reactance equal to the characteristic impedance of the quarter-wavelength transmission line and reduces the overall effective length of the feedback path.

High frequency shunt feedback amplifier topology

A method and apparatus for continuously calibrating the modulation sensitivity of a voltage controlled oscillator (VCO) within a modulator of a transmitter. In accordance with the present invention, the transmitter is coupled to the receiver in order to loop back the transmit signal. The present invention includes a baseband signal generator which generates a reference baseband signal of known amplitude during periods when no other baseband information is being applied to the transmitter by the user. A Signal and Reference Comparison Circuit (SRCC) receives the output from the demodulator and determines whether the VCO within the transmitter has the proper modulation sensitivity. If the modulation sensitivity of the VCO is not within a desired range, then a signal generated by the SRCC is applied to a baseband level control circuit to adjust the level of the baseband signal that is applied to the VCO.

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San Diego, CA, United States of America

Martin Alderton