Patent application number | Description | Published |
20120245901 | Finite Impulse Response Filter For Producing Outputs Having Different Phases - A method and system for designing and implementing a finite impulse response (FIR) filter to create a plurality of output signals, each output signal having the same frequency but at a different phase shift from the other output(s), is described. Values are determined for the resistors, or other elements having impedance values, in a FIR filter having a plurality of outputs, such that each output has the same frequency response but a different phase than the other output(s). This is accomplished by the inclusion of a phase factor in the time domain calculation of the resistor values that does not change the response in the frequency domain. The phase shift is constant and independent of the frequency of the output signal. | 09-27-2012 |
20120246208 | FIR Filter with Reduced Element Count - A finite impulse response (FIR) filter having a differential output and capable of having negative coefficients, and a method of designing the filter, is disclosed. In contrast to the prior art, in which two output signals requires the use of two identical sets of impedance devices corresponding to the Fourier coefficients that create the desired response of the filter, the described method and system uses only a single set of impedance devices, and thus approximately one-half of the number of impedance devices used in the prior art. This is accomplished by appropriately selecting which resistors contribute to which output, so that a differential output may be obtained that is substantially the same as if impedance devices corresponding to all of the coefficients were used for each signal. | 09-27-2012 |
20120246607 | System and Method for Series and Parallel Combinations of Electrical Elements - A method and system for generating and matching complex series and/or parallel combinations of nominally identical initial elements to achieve compound values having constant ratios to the initial elements and to each other is disclosed. The ratios between compound values can be held constant to almost any desired degree of accuracy, with potential errors greatly reduced from those typical in the construction of individual elements of different values. Since the initial elements are nominally identical, the ratios between values depend primarily upon the connections of the initial elements, rather than their geometry, and thus remain virtually constant regardless of variations in the manufacturing process. | 09-27-2012 |
20130106486 | Feedback in Noise Shaping Control Loop | 05-02-2013 |
20130115906 | Down-Conversion of Multiple RF Channels - A method and system is disclosed for designing a radio for down-converting RF signals to IF signals by sampling the signals in a round-robin sampling circuit and multiplying the samples by coefficients that are changed at a fixed rate equal to the rate of operation of each of the sampling circuits. The circuit is able to down-convert multiple channels simultaneously to adjacent positions in the IF band, while rejecting unwanted image signals. The method and system avoids the difficulty and cost of directly digitizing the RF signal, allowing each component to operate at a greatly reduced speed. The coefficients are selected to provide the desired transfer function while keeping the output signal centered at a desired frequency. | 05-09-2013 |
20130254253 | Buffer-less Rotating Coefficient Filter - A circuit that provides a rotating coefficient FIR filter with all necessary coefficient sets present at the same time, without the need for delay elements, devices providing for adjustable impedances, or buffers is described. An input signal is sampled in a round robin fashion by a plurality of switches and capacitors. The capacitors are connected directly to sets of impedance devices. Each set of impedance devices implements the coefficients of the desired frequency response of the filter, adjusted to compensate for the decay of samples in the capacitors between samples. The impedance devices in each set are connected to the capacitors in a different order from each other set, so that each set of impedance devices will produce the desired frequency response when a different one of the capacitor contains a new sample of the input signal. Switches connect the sets of impedance devices to an output and a virtual ground, only one switch being connected to the output at a time to provide the output signal. | 09-26-2013 |
20130285766 | Rotating Coefficient Filter - A circuit that provides a rotating coefficient FIR filter with all necessary coefficient sets present at the same time, without the need for delay elements or devices providing for adjustable impedances is described. An input signal is sampled in round robin fashion by a plurality of sample and hold devices. The outputs of the sample and hold devices are connected to sets of impedance devices. Each set of impedance devices implements the coefficients of the desired frequency response of the filter. The impedance devices in each set are connected to the sample and hold devices in a different order from each other set, so that each set of impedance devices will produce the desired frequency response when a different one of the sampling circuits contains a new sample of the input signal. Switches connect the sets of impedance devices to an output, only one switch being closed at a time to provide the output signal. | 10-31-2013 |
20140073279 | Minimizing Bandwidth in Down-Conversion of Multiple RF Channels - A method and system is disclosed for simultaneously down-converting multiple selected signals, such as RF signals, into adjacent ranges in an intermediate frequency band so that the total resulting bandwidth, and thus the sampling rate required to digitize the signal, is minimized. A first signal is down-converted into a range starting at a lowest selected frequency in the IF band. The next signal is down-converted, into a range higher than, but near or adjacent to, the down-converted range of the first signal, and so on. A guard band may be left between the signals if desired. In this way, the selected signals occupy the minimum bandwidth required. When the selection of signals to be down-converted is changed, the frequency ranges are dynamically adjusted so that the signals being down-converted always occupy the lowest ranges of the IF band. | 03-13-2014 |
20140103977 | Use of Frequency Addition in a PLL Control Loop - A method and system is disclosed in which the phase detector in a phase-locked loop is able to run at the fastest speed appropriate for a reference signal. A frequency offset is added, to the output frequency of the phase-locked loop, to alter the frequency fed to the frequency divider which would receive the output frequency in a conventional PLL to an intermediate frequency. The frequency offset is selected so that the ratio of the intermediate frequency to the reference frequency is a simple fraction, and preferably an integer, i.e., the intermediate frequency is a multiple of the reference frequency. In cases where the relationship between the output frequency and the reference frequency is largely relatively prime, the phase detector is thus able to receive signals at the frequency of the reference signal and operate at the fastest speed appropriate for the reference signal. | 04-17-2014 |
20140105269 | FIR Filter Using Unclocked Delay Elements - A system and method for filtering an analog signal with a finite impulse response (FIR) filter that does not require analog delay elements are disclosed. An analog signal is pulse-width encoded, and the pulse-width encoded signal passed to a delay line comprising unclocked delay elements, such as logic gates, rather than clocked delay elements such as are used in conventional FIR filters. The propagation of the input signal is thus due only to the delay inherent in each gate, and occurs based upon when a signal reaches the gate rather than being caused by a clock signal. As with a conventional FIR filter, weighting elements having impedance are used to weigh the output of each delay element, and the resulting outputs summed to obtain a filtered output signal. For certain signals, such a circuit and method provides a simpler way of filtering than conventional filters. | 04-17-2014 |
20140375356 | Delay Circuit Independent of Supply Voltage - A delay circuit in which the delay is independent of variations in the power supply which powers the logic gates of the delay circuit is disclosed. By separating the CMOS transistors that form each logic gate by additional CMOS bias transistors which are biased at a controlled voltage, variations in the gate delay of the inverter transistors due to variations in the power supply voltage for the inverter transistors may be minimized. In one embodiment, the constant bias voltage may be provided by a constant current source comprising a series of amplifiers each having a gain significantly less than one connected to a triple cascode. | 12-25-2014 |
20150040085 | System and Method for Series and Parallel Combinations of Electrical Elements - A method and system for generating and matching complex series and/or parallel combinations of nominally identical initial elements to achieve an arbitrary compound value is disclosed. A recursive algorithm successively adds one or more similar nominal two-terminal elements to generate a series and/or parallel compound combination of nominal elements, the compound combination having a desired impedance. The compound value, and thus the ratio between two compound values, can be determined to almost any desired degree of accuracy, with potential errors greatly reduced from those typical in the construction of individual elements of different values. Since the initial elements are nominally identical, the compound value, and the ratio between values, depends primarily upon the connections of the initial elements, rather than their geometry, and thus remain virtually constant regardless of variations in the manufacturing process. | 02-05-2015 |
20150046894 | Constrained Placement of Connected Elements - An improved method for the placement and routing of compound elements, each comprising a series/parallel combination of nominally identical elements, is disclosed. The method treats each compound element as a separate cell (the sub-circuit construct commonly used in silicon chip design) so as to treat as a unit all the nominally identical elements that make up a compound value, and place them as a single group in the design of a chip. This results in the compound elements being placed as units and routed in such a way that all of the nominal elements are located together and any effects between compound values are thus relatively localized and optimally isolated. | 02-12-2015 |