Abstract: Disclosed are systems and method for controlling frequency synthesizers. A control system can be implemented in a phase-locked loop (PLL), such as a Frac-N PLL of a frequency synthesizer, to reduce or eliminate reference spurs. In some embodiments, such a control system can include a phase detector configured to receive a reference signal and a feedback signal. The phase detector can be configured to generate a first signal representative of a phase difference between the reference signal and the feedback signal. The control system can further include a charge pump configured to generate a compensation signal based on the first signal. The control system can further includes an oscillator configured to generate an output signal based on the compensation signal. The compensation signal can be configured to reduce or substantially eliminate one or more reference spurs associated with the frequency synthesizer.

Abstract: Disclosed are systems and method for controlling frequency synthesizers. A control system can be implemented in a phase-locked loop (PLL), such as a Frac-N PLL of a frequency synthesizer, to reduce or eliminate reference spurs. In some embodiments, such a control system can include a phase detector configured to receive a reference signal and a feedback signal. The phase detector can be configured to generate a first signal representative of a phase difference between the reference signal and the feedback signal. The control system can further include a charge pump configured to generate a compensation signal based on the first signal. The control system can further includes an oscillator configured to generate an output signal based on the compensation signal. The compensation signal can be configured to reduce or substantially eliminate one or more reference spurs associated with the frequency synthesizer.

Abstract: Disclosed are circuits and method for reducing or eliminating reference spurs in frequency synthesizers. In some implementations, a phase-locked loop (PLL) such as a Frac-N PLL of a frequency synthesizer can include a phase frequency detector (PFD) configured to receive a reference signal and a feedback signal. The PFD can be configured to generate a first signal representative of a phase difference between the reference signal and the feedback signal. The PLL can further include a compensation circuit configured to generate a compensation signal based on the first signal. The PLL can further includes a voltage-controlled oscillator (VCO) configured to generate an output signal based on the compensation signal. The compensation signal can include at least one feature for substantially eliminating one or more reference spurs associated with the PLL.

Abstract: The present invention provides compounds produced by the reaction of glycidyl ethers and glycidyl esters with ether compounds including N,N,N?-trimethyl-bis-(aminoethyl)ether. N,N,N?-trimethyl-bis-(aminoethyl)ether and its derivatives can be used as polyurethane catalysts.

Abstract: The present invention provides compounds produced by the reaction of glycidyl ethers and glycidyl esters with ether compounds including N,N,N?-trimethyl-bis-(aminoethyl) ether. N,N,N?-trimethyl-bis-(aminoethyl) ether and its derivatives can be used as polyurethane catalysts.

Abstract: The present invention provides compounds produced by the reaction of glycidyl ethers and glycidyl esters with ether compounds including N,N,N?-trimethyl-bis-(aminoethyl) ether. N,N,N?-trimethyl-bis-(aminoethyl) ether and its derivatives can be used as polyurethane catalysts.

Abstract: This invention relates to an improvement in a liquid phase process for producing isopropanol by the hydrogenation of acetone in the presence of a hydrogenation catalyst; the improvement comprising; contacting acetone with hydrogen under continuous liquid phase conditions; and, employing a sponge metal catalyst promoted with an effective amount of chromium.

Abstract: A method for converting amino ether alcohols to amino ether amines by amination in the vapor phase with a catalyst comprising copper and zinc. The catalyst may also comprise an alkali, alkaline earth, or lanthanide element as a promoter.

Abstract: An integrated circuit superheterodyne radio receiver includes a notch filter coupled with an amplifier for amplifying radio frequency (RF) signals to improve image signal rejection. The notch filter includes a first oscillator circuit with a tank circuit having a resonant frequency corresponding to the unwanted image frequency signal. A control circuit includes a second oscillator circuit, a master bias circuit and a slave bias circuit. The second oscillator circuit is substantially similar to the first oscillator circuit. The master bias circuit is responsive to an amplitude of oscillatory signals in the second oscillator circuit for limiting a flow operating current such that the second oscillator circuit is restrained to operate in a marginally oscillatory state. A slave bias circuit is responsive to the master bias circuit for similarly limiting a flow of current, for operating the first oscillator circuit.

Abstract: A continuous process for the production of dimethylformamide comprising the steps: (a) reacting methyl formate and dimethylamine in a reactive distillation column under conditions to form dimethylformamide and by-product methanol; (b) vaporizing the by-product methanol and generating a liquid dimethylformamide while in said reactive distillation column; (c) removing at least a major portion of the by-product methanol as an overhead from said reactive distillation column; (d) removing a crude liquid dimethylformamide containing residual by-product methanol as a bottoms fraction from said reactive distillation column; (e) introducing said bottoms fraction containing dimethylformamide and residual by-product methanol to a purification column wherein the by-product methanol is removed from said dimethylformamide as an overhead and purified dimethylformamide is removed as a bottoms fraction; and, optionally, (f) recycling the by-product methanol removed as an overhead from the purification column to the reac

Abstract: With the rising popularity in wireless personal communication systems (PCS), there is a need for low-power, low-cost radio receivers. Low cost can be achieved by integrating the required functions as much as possible, thus minimizing the number of off-chip components. The present invention discloses a novel topology for integrating an image reject filter with a traditional low-noise amplifier (LNA) for use in the front-end of a superheterodyne receiver. Previous topologies employing additional filter stages after the LNA have suffered from poor performance and excessive current consumption. Advantageously, the topology of the present invention requires minimal additional circuitry to perform the filtering function, uses only minimal additional current and does not suffer from the same performance limitations as previous topologies.

Abstract: A novel circuit topology which provides for the digital automatic gain control of a VCO is disclosed. The topology of the VCO is based on the negative transconductance oscillator due to its intrinsically simple biasing scheme. A system parameter sensitive to the performance level of the VCO is firstly measured. A digital control signal is then generated in response to the measured system parameter. The biasing current provided by the tail circuit of the VCO is adjusted based on the value of the digital control signal. In this way, the biasing current of the VCO may be adjusted to an optimal value for all frequencies of operation. The automatic control aspects of the present invention is useful in monolithic implementations since it automatically compensates for variations in load resistance, process parameters and component tolerances without requiring expensive manual adjustments at the board level.

Abstract: Disclosed is a method of producing elementary semiconductor devices such as a field-effect transistor, a capacitor, a resistor, an inductor, a transformer, or a diode, and devices produced by said method. According to the method, a semiconductor seed layer is applied to a substrate having regions of exposed semiconductor material and regions of exposed dielectric material. The method comprises a step of disposing the substrate in a growth chamber and nucleating the seed layer by exposing the semiconductor material and dielectric material to an atmosphere of gases presented at a predetermined flow rate, temperature and pressure selected to provide contiguous growth of the seed layer, the seed layer growing in a single crystal lattice over predetermined windows within the mixed topology substrate.

Abstract: A novel circuit topology which provides for the digital automatic gain control of a VCO is disclosed. The topology of the VCO is based on the negative transconductance oscillator due to its intrinsically simple biasing scheme. A system parameter sensitive to the performance level of the VCO is firstly measured. A digital control signal is then generated in response to the measured system parameter. The biasing current provided by the tail circuit of the VCO is adjusted based on the value of the digital control signal. In this way, the biasing current of the VCO may be adjusted to an optimal value for all frequencies of operation. The automatic control aspects of the present invention is useful in monolithic implementations since it automatically compensates for variations in load resistance, process parameters and component tolerances without requiring expensive manual adjustments at the board level.

Abstract: An integrated circuit superheterodyne radio receiver includes a notch filter coupled with an amplifier for amplifying radio frequency (RF) signals to improve image signal rejection. The notch filter includes a first oscillator circuit with a tank circuit having a resonant frequency corresponding to the unwanted image frequency signal. A control circuit includes a second oscillator circuit, a master bias circuit and a slave bias circuit. The second oscillator circuit is substantially similar to the first oscillator circuit. The master bias circuit is responsive to an amplitude of oscillatory signals in the second oscillator circuit for limiting a flow operating current such that the second oscillator circuit is restrained to operate in a marginally oscillatory state. A slave bias circuit is responsive to the master bias circuit for similarly limiting a flow of current, for operating the first oscillator circuit.

Abstract: Recent trends have seen the desire for lower and lower supply voltages in radio frequency (RF) components as this leads to lower power consumption and, therefore, longer battery life. As well, lower voltages and less current means that mobile products can be made to require fewer battery cells leading to lighter, more compact devices. The present invention discloses a novel topology for providing a low-voltage voltage-controlled oscillator (VCO). The novel topology is based on the negative transconductance oscillator. However, the novel topology of the invention eliminates transistor ‘stacking’ in the oscillator circuit, thereby allowing the oscillator circuit to be operated at a supply voltage only slightly higher than the turn-on voltage for a single transistor.

Abstract: This invention relates to an improvement in a process for the production of an alkyl formamide, wherein a gas-containing carbon monoxide is reacted at elevated temperature and pressure in reaction zone with a nitrogen-containing compound selected from the group consisting of ammonia, a primary or secondary alkylamine, in the presence of a solvent and a catalyst. The improvement comprises utilizing a solvent comprising a polyethylene glycol, polypropylene glycol, polyethylenepropylene glycol, or mixtures, and an alkali metal or alkaline earth metal alkoxide of a polyethylene glycol, polypropylene glycol, polyethylenepropylene glycol or mixtures as the catalyst.

Abstract: This invention relates to an improvement in a process for the catalytic amination of an allylic alcohol of the formula:CH.sub.2 .dbd.CR--CH.sub.2 OHwhere R is hydrogen or methyl with ammonia or an amine of the formula R.sub.1 R.sub.2 NH where R.sub.1 and R.sub.2 represent hydrogen or a C.sub.1-5 hydrocarbyl group in the presence of an effective amount of a phosphorous containing catalyst to effect reaction between the allylic alcohol and the ammonia or amine to produce an allylic amine. The improvement in the process resides in utilizing a neutral group IIA metal phosphate as a catalyst component. Calcium phosphate is preferred and the catalyst.