2345 results about "Output impedance" patented technology

An RF antenna coupling structure includes a first transformer, a second transformer, and a transformer balun. The first transformer includes a primary winding and a secondary winding, wherein the primary winding of the first transformer is operably coupled to a power amplifier, and wherein the secondary winding of the first transformer has a desired output impedance corresponding to the operational needs of the power amplifier. The second transformer includes a primary winding and a secondary winding, wherein the primary winding of the second transformer is operably coupled to a low noise amplifier, and wherein the secondary winding of the second transformer has a desired output impedance corresponding to the needs of the low noise amplifier. The transformer balun includes a differential winding and a single-ended winding, wherein the differential winding is operably coupled to the secondary windings of the first and second transformers and the single-ended winding is operably coupled to an antenna.

The power of DC electrical sources is combined onto a DC buss, such that each source behaves independently from any other source attached to the buss. In one embodiment, a converter module is attached to each of a plurality of solar photovoltaic panels and its output is attached in a parallel manner to a common buss that forms the input to a DC AC inverter. The converter module includes a Maximum Power Point Tracking component that matches the output impedance of the panels to the input impedance of the converter module. The converter also includes a communication component that provides parametric data and identification to a central inverter. Data generated by each converter module is transmitted over the power line or by wireless means and is collected at the inverter and forwarded to a data collection and reporting system.

Methods and systems for power control with optimum power efficiency with a multi-port distributed antenna are disclosed and may include selectively enabling one or more power amplifiers (PAs) coupled to the antenna. The selective enabling may be based on a desired output power radiated from the antenna, and the PAs may be coupled to ports on the antenna based on an output impedance of the PAs and a characteristic impedance of the ports. Each of the PAs may be configured for maximum efficiency in different power ranges. The power ranges may be inversely proportional to the output impedance of the PAs. The output power may be monitored utilizing a power detector, such as an envelope detector, coupled to the antenna. The antenna may be integrated on a chip with the one or more PAs or may be located external to the chip. The antenna may include a microstrip antenna.

An output buffer for driving a capacitively-terminated transmission line produces a waveform which comprises a first portion during which the waveform transitions from a voltage V1 to a voltage V2; a second portion during which it remains fixed at V2; a third portion during which it transitions to a voltage V3; and a fourth portion during which it remains fixed at V3. The waveform is created within a unit interval whenever successive data bits transition between logic states. The first and second portions are generated with circuitry arranged such that V2 is maximized by reducing the buffer's output impedance. The fourth portion is generated with circuitry which has a non-zero output impedance preferably equal to the transmission line's characteristic impedance, to absorb transitions reflected back to the source circuitry by the capacitive termination.

Fully-buffered dual in-line memory modules (FB-DIMM) include advanced memory buffers (AMBs) having enhanced skew, slew rate and output impedance control. The AMB includes user accessible registers that can be programmed to carefully control the edge placement (or phase) of signals generated from the AMB to multiple DRAMs on the module. This control of edge placement, which may be performed independently for each group of signals: clock (CLK, CLK#), command (RAS, CAS, WE), address (including bank address), data (DQ) and data strobe (DQS), provides 360 degrees of control (or one period). This means that any group of signals can be moved independently by one complete period relatively to any other group.

An antenna for a communications device having configurable elements controlled to modify an antenna impedance and / or an antenna resonant frequency to improve performance of the communications device. The antenna impedance is controlled to substantially match to an output impedance of a power amplifier that supplies the antenna with a signal for transmission. The antenna resonant frequency is controlled to overcome the effects of various operating conditions that can detune the antenna or in response to an operable frequency band.

A switched-mode Class F power amplifier is provided for parallel connection with at least one other like amplifier, within a Chireix architecture, for combining the signals output therefrom. An input component includes at least one active device configured to be alternately switched by a signal input thereto to present an amplified signal corresponding to the input signal and constituting a low output impedance voltage source. A lumped element impedance inverter is provided between the input component and an output resonator component, the impedance inverter being configured for transforming the low output impedance voltage source to instead constitute a high output impedance current source configured for said parallel connection. In accordance with the invention, the negative reactive component values required by the impedance inverter are eliminated and effectively provided by incorporating those values into pre-selected reactive components of the input and output components. Further, a source-drain parasitic capacitance across the active device is eliminated by one or more pre-selected reactive components of the input component, the value(s) of which effectively compensate for the parasitic capacitance.

An object of the present invention is to allow the miniaturization of a mobile communication equipment and the reduction of consumption power, and to improve the electrical characteristics of a final stage amplifier. An inputted RF signal is amplified to a specified transmission output by a final stage amplifier, the output power and a reflected wave generated by mismatching between an output impedance of the final stage amplifier and a load impedance connected to an output side of the final stage amplifier are detected by a directional coupler. Two switches are selectively switched in a time division manner, a DC voltage corresponding to the reflected wave is selected, a comparator compares a threshold voltage with the DC voltage, a switch is switched by an output of the comparator outputted in accordance with the comparison, and gate voltages are selectively applied to the final stage amplifier.

A multi-level power amplifier architecture using a multi-tap transformer implemented on a single CMOS integrated circuit wireless communications device is described. By providing a multi-tap transformer for coupling a plurality of power amplifiers to a shared output impedance, such as an antenna, power transmission may be made at different levels while maintaining efficiency. With a multi-tap transformer having “N” taps featuring “N” different impedance levels, each tap may be connected to an amplifier cell which delivers power into the transformer at the tap for coupling to the output load. Any one of the “N” amplifier cells can be turned on at once along with any combination of the “N” amplifier cells.