Abstract: A first device provides both power and data to a second device over a power line connection between the two devices. The first device includes a power line extending from a power supply, a ground line extending from a ground, a first impedance in the power line, and a second impedance in the ground line. A modulator comprised of a transistor and modulator impedance is between the first impedance and the second impedance, and a tank capacitor is between the power line and the ground line, outside the first impedance and second impedance. A comparator is coupled between the first and second impedance. A switch may be included to short out the first and second impedance, thereby enabling transmission of only power for period of time, and return to a mode of transmitting both data and power. The first device may also receive data from the second device over the power line connection.

Abstract: Embodiments of the present invention disclose a filter apparatus, a base station system, and a method for frequency channel switching. In application of technical solutions provided by the embodiments of the present invention, the grounding probe connected to the electrical ground contacts or approaches the resonator to short-circuit or disturb a resonant cavity that includes the resonator, so as to reject output of an input signal of the filter apparatus and finally achieve an effect of closing the filter apparatus; when the filter apparatus is used in combination with multiple other filter apparatuses, and when the filter apparatus is closed, spurious signals of the other filter apparatuses are not propagated to an antenna port through the filter apparatus.

Abstract: The A/D conversion apparatus includes an A/D converter for converting a potential difference between a reference voltage input and a voltage input to be measured to a digital signal and outputting the digital signal; a first switch connected between a voltage source to be measured and the voltage input to be measured; a first sampling capacitor having a first end connected to the voltage input to be measured and to a first end of the first switch, and having a second end connected to a reference power source; a second switch connected between a reference voltage source and the reference voltage input; a second sampling capacitor having a first end connected to the reference voltage input and to a first end of the second switch, and having a second end connected to the reference power source; and an impedance adjusting circuit, which is connected between the reference voltage source and a second end of the second switch, for changing, in stepwise fashion, impedance between the reference voltage source and the

Abstract: A system and methods are provided for switching a signal from a first transmission media having a characteristic impedance to a second transmission media. The system includes a driver for driving a signal, the driver having a driver input having a high impedance relative to a characteristic impedance of the first transmission media and the driver having a driver output having an impedance equal to the characteristic impedance of the first transmission media. A first switch couples the driver output either to the first transmission media or to the second transmission media and couples a signal from the first transmission media, which is coupled to the driver input, either to the first transmission media or to the second transmission media.

Abstract: A laser emits a laser beam with a predetermined frequency, serving as pumping light, to a double resonance section. A VCO oscillates a predetermined frequency signal that is the origin of a microwave. An oscillator oscillates a modulation signal and a low frequency signal to be a reference signal for a sync detection. A synthesizer generates a microwave acquired by subjecting the predetermined frequency signal to multiplication and phase modulation in accordance with the predetermined frequency signal and the modulation signal, and applies the microwave to the double resonance section. A photosensor detects a component of the laser beam modulated by the double resonance section. A PSD detects the level and phase of an output signal of the photosensor with the reference signal. A sweep signal generator generates a sweep signal for the microwave.

Abstract: An automatic switching unit for connection to a modem at a remote site in a data communications network. The switching unit normally connects the modem to a primary data transmission path. If the primary path malfunctions, a central site operator can telephone the remote site and establish a secondary data transmission path. The switching unit answers the incoming calls and automatically disconnects the modem from the primary data transmission path. Once the primary data transmission path has been repaired, the central site operator causes the switching unit to return communications to the primary data transmission path. In one embodiment, this transfer can be made while maintaining communications over the secondary data transmission path.

Abstract: A direct current transmission system includes two separate parallel transmission circuits each including convertors. The transmission circuits are bipolar. One pole of one of the circuits is provided with pole reversing switches for the convertors of that pole. The poles of each of the circuits are connected in parallel by transmission lines. Switches are provided by which one of the transmission lines of one circuit can be disconnected from that circuit and connected across a faulty transmission line of the other circuit, which meanwhile is disconnected therefrom, so as to substitute for the disconnected transmission line of the second circuit.