Abstract: Systems and methods for generating a radio frequency (RF) signal by a digital-to-analog converter (DAC) with transmission frequency within a wide transmission frequency range are described. An output reactance of the DAC coupled (directly or indirectly) to one or more antennas corresponds to the transmission frequency of the RF signals. Multiple embodiments of the DAC are described to include circuitry for tuning the output reactance of the DAC, and therefore, shifting a center frequency to select a transmission frequency range (from multiple transmission frequency ranges) for providing the RF signals.

Abstract: Systems and methods for generating a radio frequency (RF) signal by a digital-to-analog converter (DAC) with transmission frequency within a wide transmission frequency range is described. An output reactance of the DAC coupled (directly or indirectly) to one or more antennas corresponds to the transmission frequency of the RF signals. Multiple embodiments of the DAC are described to include circuitry for tuning the output reactance of the DAC, and therefore, shifting a center frequency to select a transmission frequency range (from multiple transmission frequency ranges) for providing the RF signals.

Abstract: The present invention discloses a lead-acid battery electrode plate for preventing lead-acid battery from lead (II) sulfate crystal growth piercing and enhancing the battery formation efficiency. The lead-acid battery electrode plate comprises an electricity collector layer as an electric current channel, and two air permeable layers respectively placed on both sides of the electricity collector layer, wherein non-metallic sheet materials having porous structures are used as air-permeable channel of the air-permeable layers, and the first air-permeable layer is the same as or different from the second air-permeable layer.

Abstract: An interface module coupled between a host device and a wireless device is disclosed. The interface module includes a connector, having a first part covered in a first case with a first depth and a second part covered in a second case with a second depth; and a control circuit coupled to the first part of the connector, for controlling data transmission between the host device and the wireless device; wherein the second case is made of a conductive material and which can be further covered by an absorptive material.

Abstract: An interface module coupled between a host device and a wireless device is disclosed. The interface module includes a connector, having a first part covered in a first case with a first depth and a second part covered in a second case with a second depth; and a control circuit coupled to the first part of the connector, for controlling data transmission between the host device and the wireless device; wherein the second case is made of a conductive material and which can be further covered by an absorptive material.

Abstract: A method for preparing a flame retardant modified acrylonitrile-based copolymer, includes: prepolymerizing a first composition to obtain a first prepolymer solution including a first prepolymer; prepolymerizing a second composition to obtain a second prepolymer solution including a second prepolymer; and mixing the first and second prepolymer solutions and subjecting a mixture of the first and second prepolymers to polymerization to obtain a flame retardant modified acrylonitrile-based copolymer solution containing a flame retardant modified acrylonitrile-based copolymer.

Abstract: A method for preparing a flame retardant modified acrylonitrile-based copolymer, includes: prepolymerizing a first composition to obtain a first prepolymer solution including a first prepolymer; prepolymerizing a second composition to obtain a second prepolymer solution including a second prepolymer; and mixing the first and second prepolymer solutions and subjecting a mixture of the first and second prepolymers to polymerization to obtain a flame retardant modified acrylonitrile-based copolymer solution containing a flame retardant modified acrylonitrile-based copolymer.

Abstract: An interface module coupled between a host device and a wireless device is disclosed. The interface module includes a connector, having a first part covered in a first case with a first depth and a second part covered in a second case with a second depth; and a control circuit coupled to the first part of the connector, for controlling data transmission between the host device and the wireless device; wherein the second case is made of a conductive material and which can be further covered by an absorptive material.