Abstract: A digital delta-sigma modulator (DDSM) is disclosed with an input signal x[n], an output signal y[n], a quantization error signal e[n] and a dither signal d[n], having an equation described in the z-domain by Y(z)=STF(z)X(z)+DTF(z)D(z)?NTF(z)E(z) wherein Y(z), X(z), D(z) and E(z) are z-transforms of the output signal, the input signal, the dither signal, and the quantization error signal, and wherein STF(z), DTF(z) and NTF(z) correspond to a transfer function of the input signal, a transfer function of the dither signal, and a transfer function of the quantization error signal, and wherein the transfer function of the quantization error signal is of the form: NTF ? ( z ) = Az - Q ( 1 + ? i = 1 K c i ? z - i ) where A, Q and K are constants, coefficients ci are real valued and cK?0 and wherein at least one of the zeroes zj of ( 1 + ? i = 1 K c i ? z - i ) satisfies zj?+1 for j=1, 2, . . .

Abstract: An apparatus for mitigating nonlinearity-induced spurs and noise in a fractional-N frequency synthesizer A digital delta-sigma modulator (DDSM) is disclosed with an input signal x[n], an output signal y[n], a quantization error signal e[n] and a dither signal d[n], having an equation described in the z-domain by Y(z)=STF(z)X(z)+DTF(z)D(z)?NTF(z)E(z) wherein Y(z), X(z), D(z) andE(z) are z-transforms of the output signal, the input signal, the dither signal, and the quantization error signal, and wherein STF (z), DTF(z) and NTF(z) correspond to a transfer function of the input signal, a transfer function of the dither signal, and a transfer function of the quantization error signal, and wherein the transfer function of the quantization error signal is of the form: NTF ? ( z ) = Az - Q ( 1 - z - 1 ) ? ( 1 + ? i = 1 K c i ? z - i ) where A , Q and K are constants, coefficients ci are real valued and cK?0 and wherein at least one of the zeroes zj of ( 1 + ? i =

Abstract: The present invention provides a fractional-N frequency synthesizer comprising a divider controller comprising a multistage noise Shaping (MASH) digital delta-sigma modulator comprising L error feedback modulator (EFM) stages, wherein the jth EFM stage is configured to receive as an input the sum of the error of the preceding EFM stage and a high amplitude dither signal derived from the error of the kth EFM stage, where 1?j?k?L.

Abstract: The present invention provides a probability mass redistributor device comprising an input port and an output port. The device comprises a mapping block configured to perform a selected mapping function from a plurality of mapping functions on a random bitstream to generate an output signal having a desired probability mass function, at least one difference block, wherein the input to the at least one difference block comprises the output from the mapping block, and the output of the at least one difference block produces a modulation term, and wherein the output of each difference block is the difference between a previous value of the input signal to the block and a current value of the input signal to the block, and a summing block for summing a signal received by the input port and the modulation term to form an output signal.

Abstract: The present invention provides a fractional-N frequency synthesizer comprising a divider controller comprising a multistage noise Shaping (MASH) digital delta-sigma modulator comprising L stages, wherein the jth stage is configured to receive as an input the sum of the error of the preceding stage and a high amplitude dither signal derived from the error of the kth stage, where 1?j?k?L.

Abstract: The present invention provides a probability mass redistributor device comprising an input port and an output port. The device comprises a mapping block configured to perform a selected mapping function from a plurality of mapping functions on a random bitstream to generate an output signal having a desired probability mass function, at least one difference block, wherein the input to the at least one difference block comprises the output from the mapping block, and the output of the at least one difference block produces a modulation term, and wherein the output of each difference block is the difference between a previous value of the input signal to the block and a current value of the input signal to the block, and a summing block for summing a signal received by the input port and the modulation term to form an output signal.

Abstract: A nested mixed-radix DDSM can guarantee zero systematic frequency error when used as a divider controller in a fractional-N frequency synthesizer is described. This disclosure presents a nested cascaded mixed-radix DDSM architecture which can also guarantee zero systematic frequency error. In addition, the disclosure allows one to use higher order auxiliary modulators and shaped dither signal to eliminate feedthrough spurs completely. By increasing the number of levels in the cascade, the moduli of the individual modulator stages can be reduced, thereby increasing the speed of the synthesizer.

Abstract: The present invention provides a fractional-N frequency synthesizer comprising a divider controller comprising a multistage noise Shaping (MASH) digital delta-sigma modulator comprising L stages, wherein the Lth stage is configured to receive as an input a high amplitude dither signal.

Abstract: The present invention provides a fractional-N frequency synthesizer comprising a divider controller comprising a multistage noise Shaping (MASH) digital delta-sigma modulator comprising L stages, wherein the Lth stage is configured to receive as an input a high amplitude dither signal.

Abstract: A nested mixed-radix DDSM can guarantee zero systematic frequency error when used as a divider controller in a fractional-N frequency synthesizer is described. This disclosure presents a nested cascaded mixed-radix DDSM architecture which can also guarantee zero systematic frequency error. In addition, the disclosure allows one to use higher order auxiliary modulators and shaped dither signal to eliminate feedthrough spurs completely. By increasing the number of levels in the cascade, the moduli of the individual modulator stages can be reduced, thereby increasing the speed of the synthesizer.

Abstract: Methods and systems are disclosed that provide a radio frequency synthesizer that generates precise frequencies over a large radio frequency range. The radio frequency synthesizer can provide a high resolution of frequency generation and still provide precise frequencies over a range of radio frequencies. The precision and resolution while maintaining a large operating range come from the ability of the frequency synthesizer to generate frequencies as a product of a plurality of moduli. For example, the frequency can be generated from a reference frequency using a first modulus and a second modulus. The plurality of modulo can be implemented using nested digital delta-sigma modulators in a fractional-N frequency synthesizer.

Abstract: At least one embodiment of the invention relates to an injection-locked frequency divider adapted to generate a signal at an output frequency from an input frequency over a large range of input frequencies, wherein said input frequency is either an even or an odd integer multiple of the output frequency.

Abstract: The invention provides a digital modulator system for use in a fractional-N frequency synthesizer, said system comprising: a first pipelined modulator configured to receive a digital signal via a bus signal; a second pipelined modulator configured to receive a part of said digital signal; and said system is adapted to split the bus signal by passing least significant bits (LSBs) of said digital signal through the second modulator, combining the output of said second modulator with the most significant bits (MSBs) of said digital signal, and adapted to pass the combined signal through said first pipelined modulator. The combination of bus-splitting and pipelining in the modulator system is configured to provide an output signal to maximize the update rate of a multi-modulus divider of said fractional-N frequency synthesizer.

Abstract: An electrical switch performs multi-polar switching. A HDFET structure has a source (2) at one terminal and two drains (3(a) and 3(b)) providing isolated terminals at the opposite end. The drains (3(a) and 3(b)) are separated by an insulator (8). N+ gates (6, 7) are at each side of a channel (5) linking the source (2) with the drains (3(a), 3(b)). Bias of the gates (6, 7) is controlled to control depletion regions (21, 22) to switch on or off current flow (A, B) between the source (2) and the drains (3(a), 3(b)).