Abstract: Methods and systems are provided for spreading spectral density of pulse streams during digital to analog conversion. An example system may comprise an accumulator circuit, a bit generator circuit, and a feedback circuit. The accumulator circuit may be operable to receive a signal to be spread and generate an output based on the signal to be spread and on one or more inputs generated within the system. The bit generator circuit may be operable to input into the accumulator circuit sequences meeting at least one particular criterion. The feedback circuit may be operable to apply an adjustment to a signal corresponding to an output of the accumulator circuit to generate a feedback signal, and input the feedback signal into the accumulator circuit.

Abstract: An outdoor satellite receiving unit (ODU) receives several independent satellite signals, selects two signals with a switch matrix, downconverts the two signals to a bandstacked signal with a high and a low band signal, and outputs the bandstacked signal on the same cable to receiver units. Several satellite signals can be selected in groups of two or more and output to independent receiver units. Signal selecting is performed at the received radio frequency (RF) and bandstacking is performed with a single downconversion step to an intermediate frequency (IF). Channel stacking on the same cable of more than two channels from several satellites can be achieved by using frequency agile downconverters and bandpass filters prior to combining at the IF output. A slow transitioning switch minimizes signal disturbances when switching and maintains input impedance at a constant value.

Abstract: Methods and systems are provided for spreading spectral density of pulse streams during digital to analog conversion. An example system may comprise an accumulator circuit, a bit generator circuit, and a feedback circuit. The accumulator circuit may be operable to receive a signal to be spread and generate an output based on the signal to be spread and on one or more inputs generated within the system. The bit generator circuit may be operable to input into the accumulator circuit sequences meeting at least one particular criterion. The feedback circuit may be operable to apply an adjustment to a signal corresponding to an output of the accumulator circuit to generate a feedback signal, and input the feedback signal into the accumulator circuit.

Abstract: Systems and methods for correcting frequency error in a received signal include: receiving a satellite signal, the satellite signal having a bandwidth and a center frequency; determining the profile of the satellite signal; computing the center frequency of the satellite signal based on the profile of the received signal; and generating a reference signal at the computed center frequency. The systems and methods may further include computing a center frequency of each of a plurality of satellite signals based on the computed center frequency. Determining the profile may include sweeping a tuner above and below a given reference frequency; measuring the received signal strength during the sweeping operation; and determining the profile based on the received signal strength.

Abstract: Systems and methods for provided for reducing interference caused by leakage of signals generated by a spread spectrum phase lock loop (SS PLL). Output of SS PLL may be processed to reduce interference. For example, a sinusoidal spreading signal may be used to spread the output of the SS PLL. A notch filter tracks the frequency of the output of the SS PLL to steer the notch in the filter to the instantaneous frequency output from the SS PLL, thus allowing the notch filter to be placed in the path of signals that have unwanted leakage from the SS PLL.

Abstract: A circuit may include a first voltage regulator to supply a main circuit and a second voltage regulator to supply a test circuit. The test circuit may produce a test signal having a characteristic dependent on the second regulated supply voltage. A controller may adjust second voltage regulator to a threshold level to induce a change in the characteristic of the test signal. The controller may adjust the first voltage regulator based on the threshold level of the second regulated supply voltage.

Abstract: Systems and methods for generating a spurious signal cancellation signal, the system comprising two direct digital synthesizers (DDS). The first DDS provides phase tracking to correct for rounding errors. The second DDS outputs a frequency that is exactly equal to N/M*CLK, where N and M are values selected to set the output frequency equal to the frequency of a spurious signal to be cancelled, and CLK is a clock frequency used to clock the first and second DDS circuits.

Abstract: A multi-output switched mode power supply may include a power circuit and a controller to control the power circuit. A combiner circuit may produce a single feedback signal based on the regulated output voltages produced by the switched mode power supply.

Abstract: Methods and systems for frequency generation may comprise in a low-noise block down-converter (LNB) comprising an analog-to-digital converter (ADC) and a channel stacking switch (CSS): receiving a first satellite signal centered at a first frequency; receiving a second satellite signal centered at a second frequency; combining the first and second satellite signals to form a combined signal; the analog-to-digital converter transforming the combined signal from an analog signal to a digital signal; providing the digital signal to the CSS; receiving a third satellite signal centered at a third frequency; receiving a fourth satellite signal centered at a fourth frequency; translating the third satellite signal to a fifth frequency, combining the translated third satellite signal with fourth satellite signals to form a second combined signal; a second analog-to-digital converter transforming the combined signal from an analog signal to a second digital signal; and providing the second digital signal to the CSS.

Abstract: A method and apparatus in which a Tap-Weight Computer (TWC) calculates a Tap-Weight Vector (TWV). The TWV is coupled to a register in each of a plurality of adaptive filter modules. Each such adaptive filter module includes several adaptive filters that each include a tapped delay line. The input to the tapped delay line of each such adaptive filter is one of a plurality of potential interfering signals. The TWV controls the weighting of the outputs from the taps off the delay line. The weighted outputs from each tapped delay line are then subtracted from a received signal which potentially includes interference from the potential interfering signals. The TWC is multiplexed to each of the plurality of adaptive filters so that each adaptive filter is loaded with a TWV calculated by the TWC to reduce the amount of interference contributed by a particular potential interfering signal coupled to an input to that particular adaptive filter.

Abstract: 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.

Abstract: Systems and methods are provided for handling interference during communication of signals. A control signal based on leakage between the transmit path and the receive path, at least one signal applied in the transmit path during transmission of signals, and at least one signal generated in the receive path during processing of received signals. The control signal may then be applied into the receive path for use in completing processing of the received signals. One or more characteristics associated with the control signal may be set and/or adjusted based on one or more control signals applied in the transmit path. Characteristics of signals in the transmit path that may leak into the receive path may be tracked, and the control signal may be adjusted based on these Characteristics. Transmit power may be tracked, and the control signal may be adjusted based on the tracking of the transmit power.

Abstract: Methods and systems for frequency generation may comprise receiving a satellite signal the satellite signal having a center frequency; determining an amplitude response profile of the satellite signal; and computing the center frequency of the satellite signal based on the amplitude response profile of the received signal; and generating a reference signal at the computed center frequency. A center frequency of each of a plurality of satellite signals may be computed based on the computed center frequency. The determining the amplitude response profile may include: sweeping a tuner above and below a given reference frequency; measuring the received signal strength during the sweeping operation; and determining upper and lower rolloff points of the signal based on the measured signal strength.

Abstract: Methods and systems are provided for spreading spectral density of pulse streams during digital to analog conversion. An example spreading circuit may comprise an accumulator circuit, a bit generator circuit, a comparator circuit, and an inverter circuit. The accumulator circuit may be operable to receive a signal to be spread and generate an output based on the signal to be spread and at least one other input. The bit generator circuit may be operable to input into the accumulator circuit zero-sum sequences. The comparator circuit may be operable to provide a stream of pulses based on the output of the accumulator circuit. The inverter circuit may be operable to invert output of the comparator circuit, wherein output of the inverter circuit is input into the accumulator circuit.

Abstract: A method and apparatus in which a Tap-Weight Computer (TWC) calculates a Tap-Weight Vector (TWV). The TWV is coupled to a register in each of a plurality of adaptive filter modules. Each such adaptive filter module includes several adaptive filters that each include a tapped delay line. The input to the tapped delay line of each such adaptive filter is one of a plurality of potential interfering signals. The TWV controls the weighting of the outputs from the taps off the delay line. The weighted outputs from each tapped delay line are then subtracted from a received signal which potentially includes interference from the potential interfering signals. The TWC is multiplexed to each of the plurality of adaptive filters so that each adaptive filter is loaded with a TWV calculated by the TWC to reduce the amount of interference contributed by a particular potential interfering signal coupled to an input to that particular adaptive filter.

Abstract: Systems and methods for canceling cross-coupled satellite signals in a LNB IC include receiving a first satellite signal at a first input of the LNB IC and filtering the first satellite signal using a first adaptive filter, the first adaptive filter having first filter coefficients; combining the adjusted first satellite signal with a second satellite signal received at a second input of the LNB IC to generate a first combined satellite signal; measuring the total output power of the combined satellite signal; changing the filter coefficients of the first adaptive filter; remeasuring the total output power of the first combined satellite signal after the changing of the first filter coefficients to determine whether the total power of the first combined satellite signal has decreased.

Abstract: Systems and methods for generating a spurious signal cancellation signal, the system comprising two direct digital synthesizers (DDS). The first DDS provides phase tracking to correct for rounding errors. The second DDS outputs a frequency that is exactly equal to N/M*CLK, where N and M are values selected to set the output frequency equal to the frequency of a spurious signal to be cancelled, and CLK is a clock frequency used to clock the first and second DDS circuits.

Abstract: Methods and systems for frequency generation may comprise a circuit with a first input coupled to receive a first satellite signal at a first satellite downlink frequency, a second input coupled to receive a second satellite signal at a second satellite downlink frequency, and a first analog-to-digital converter (ADC) having an input coupled to receive the first satellite signal. The first ADC may be configured to create a first digital output signal representing the first satellite signal. A second ADC having an input coupled to receive the second satellite signal may be configured to create a second digital output representing the second satellite signal. The circuit may comprise a dielectric resonator oscillator having an output and a clock generator circuit having an input coupled to the oscillator output and configured to output one or more clocks used by the first and second ADCs.

Abstract: Systems and methods for correcting frequency error in a received signal include: receiving a satellite signal, the satellite signal having a bandwidth and a center frequency; determining the profile of the satellite signal; computing the center frequency of the satellite signal based on the profile of the received signal; and generating a reference signal at the computed center frequency. The systems and methods may further include computing a center frequency of each of a plurality of satellite signals based on the computed center frequency. Determining the profile may include sweeping a tuner above and below a given reference frequency; measuring the received signal strength during the sweeping operation; and determining the profile based on the received signal strength.

Abstract: Methods and systems for frequency generation may comprise in a low-noise block down-converter (LNB) comprising an analog-to-digital converter (ADC) and a channel stacking switch (CSS): receiving a first satellite signal centered at a first frequency; receiving a second satellite signal centered at a second frequency; combining the first and second satellite signals to form a combined signal; the analog-to-digital converter transforming the combined signal from an analog signal to a digital signal; providing the digital signal to the CSS; receiving a third satellite signal centered at a third frequency; receiving a fourth satellite signal centered at a fourth frequency; translating the third satellite signal to a fifth frequency, combining the translated third satellite signal with fourth satellite signals to form a second combined signal; a second analog-to-digital converter transforming the combined signal from an analog signal to a second digital signal; and providing the second digital signal to the CSS.