64results about "Amplifiers with tubes" patented technology

An aspect of a power amplifier according to the present invention is a power amplifier that amplifies a modulated signal including amplitude modulated components and phase modulated components, the power amplifier including a first voltage source 21 that amplifies low-frequency components of the amplitude modulated components of the modulated signal to output a first voltage VC_L, a second voltage source 22 that amplifies high-frequency components of the amplitude modulated components of the modulated signal to output a second voltage VC_H, a current source 24 that amplifies amplitude components of the modulated signal to output a current, a combiner circuit 23 that combines the first voltage VC_L, the second voltage VC_H, and a current IM to generate a modulated power supply signal VOUT, and an RF amplifier 30 that amplifies a signal obtained by up-converting the modulated signal to a carrier frequency and outputs the amplified signal after modulating amplitude of the amplified signal by the modulated power supply signal VOUT. In this way, power efficiency of a circuit that generates a modulated power supply can be improved.

An apparatus amplifies RF signals in a communication system by using a first directional coupler having at least two inputs and at least two outputs; at least two RF amplifiers, where an input of each RF amplifier is connected to a different one of the at least two outputs of the first directional coupler; and a second directional coupler having at least two inputs and at least two outputs, where each one of the at least two inputs is connected to an output of a different one of the at least two RF amplifiers. The at least two outputs of the second directional coupler are connected to at least two antennas, respectively.

A transceiver front end includes a transmit / receive (T / R) switch, a first balun, a second balun, a low noise amplifier, a power amplifier, and compensation circuitry. The T / R switch is operably coupled to an antenna for receiving inbound radio frequency (RF) signals and for transmitting outbound RF signals. The first balun includes a single ended winding and a differential winding, where the single ended winding is operably coupled to the T / R switch. The second balun includes a single ended winding and a differential winding, where the single ended winding is operably coupled to the T / R switch. The low noise amplifier is operably coupled the differential winding of the first balun. The power amplifier is operably coupled to the differential winding of the second balun. The compensation circuitry is operably coupled to the first balun to compensate for at least one of phase imbalance, amplitude imbalance, and impedance imbalance of the first balun.

There is described a two-channel method for determining at least one output signal from variable input signals of sent by a transmitter, using two independent channels and consisting in alternately guiding the in put signals to said channels, wherein a multiplexer is used for switching said channels. A microprocessor contained in said channels delivers input test signals transmitted to the channel not currently receiving any variable input signal. Said channel transmits output signals compared with an expected value in order to verify the channel correct operation. Simultaneously, the other channel produces an output signal. Afterwards, the multiplexer switches a control signal.

The present invention uses an electromagnetic device for amplifying an input signal without the use of amplifiers, power supplies, and inverter / converter circuits. The present invention routes an input signal through an electromagnetic device for amplification of the input signal for later use by various loads.

Aspects of a method and system for a low power fully differential noise canceling low noise amplifier (NC LNA) are provided. The NC LNA may receive signals via a single ended input and may generate an amplified symmetric differential output from the received signals. The NC LNA may utilize capacitor dividers, such as a capacitor bank, in the single ended input in order to provide impedance transformation that enables low power operation and matching to an input port. The NC LNA may generate one portion of the amplified symmetric differential output via a voltage divider, which may comprise a plurality of capacitors, such as a capacitor bank. The NC LNA may be implemented utilizing one or more circuits.

Aspects of a method and system for a low power fully differential noise canceling low noise amplifier (NC LNA) are provided. The NC LNA may receive signals via a single ended input and may generate an amplified symmetric differential output from the received signals. The NC LNA may utilize capacitor dividers, such as a capacitor bank, in the single ended input in order to provide impedance transformation that enables low power operation and matching to an input port. The NC LNA may generate one portion of the amplified symmetric differential output via a voltage divider, which may comprise a plurality of capacitors, such as a capacitor bank. The NC LNA may be implemented utilizing one or more circuits.

A circuit having a sensor with a stray capacitance value. An output from the sensor is connected to the input of an amplifier while a negative capacitance circuit is electrically connected in parallel with the sensor output. The negative capacitance circuit reduces the effect of the sensor stray capacitance to provide an increased bandwidth and decreased noise on the amplifier output.

Disclosed is a cascade voltage amplifier for producing an amplified output in pulse or continuous wave form comprises at least one non-final stage with an electron tube configured as a switching and Class A or C amplifying structure. A final stage comprises an electron tube configured as a Class A or C amplifying structure. The at least one non-final stage and the final stage are connected in series, and the amplified output has a voltage of at least 1000 volts. Further disclosed is a method of activating a plurality of cascaded electron tube stages within a common vacuum enclosure. Beneficially, a sufficient amount of energy supplied to the first stage serially propagates through any intervening stage to the final stage so as to facilitate activation of all tube stages.

An amplifier is provided using digital potentiometer integrated circuits to control the tone of a vacuum tube preamplifier allowing digital control of the analog signal path of the amplifier. Using digital potentiometer integrated circuits to control the tone of a vacuum tube preamplifier results in an amplifier that preserves the unique tone quality of a vacuum tube amplifier that offers the flexibility, versatility, and user-friendly features of a digitally controlled amplifier, such as the ability to save and recall amplifier settings. The amplifier of the present invention is especially applicable for use with musical instruments such as for example, electric guitars.

Systems and methods are provided for a transformer or balun function with reference enhancement. The systems and methods may include a transformer having at least a primary winding and a secondary winding for reference enhancement, where the primary winding includes a center tap, where the secondary winding includes a first port and a second port, and an electrical connection that electrically connects the second port and the center tap of the primary winding to provide a common reference for the primary winding and the secondary winding. The primary winding of the transformer may be configured to receive differential outputs of a power amplifier, and the transformer may be configured to convert the differential outputs from a balanced signal to an unbalanced signal available at the first port of the secondary winding.

Methods and apparatus contemplate: an output transformer having at least first and second separate primary windings and at least one secondary winding, each winding including a first (in phase) end and a second (out of phase) end; at least first and second active elements, each having at least a pair of power terminals and a control terminal, one power terminal of each active element being coupled to a common node; and a switching circuit operable to change a circuit configuration of the first and second primary windings and the active elements between a class A mode and a class A / B mode.

An amplifier circuit includes a pair of amplifying devices, a first balun coupled between an input port of the amplifier circuit and RF input ports of the pair of amplifying devices and a second balun coupled between RF output ports of the pair of amplifying devices and an output port of the amplifier circuit wherein the first and second baluns are configured such that the amplifier circuit operates under open condition for signals at a second harmonic frequency even when the second harmonic frequency is within an operating frequency band of a fundamental frequency of the amplifier circuit. In one embodiment, the amplifier circuit includes a bypass circuit which selectively couples balun ports to ground such that in response to a first control signal, the amplifier circuit operates in an amplifying mode and in response to a second control signal, the amplifier circuit operates in a bypass mode.

A differential to single ended converting circuit includes a transconductance circuit having input terminals for receiving differential input voltages and having a first current output terminal for outputting a first current and a second current output terminal for outputting a second current; an offset cancellation circuit having a first controllable current source connected to the first current output terminal and a second controllable current source connected to the second current output terminal; a first transimpedance circuit having an input terminal connected to the first current output terminal and an output terminal for outputting a first voltage; a second transimpedance circuit having an input terminal connected to the second current output terminal and an output terminal for outputting a second voltage; and a first inverter having an input terminal connected to the output terminal of the first transimpedance circuit and an output terminal for outputting a first single ended output voltage.

A vacuum tube circuit is capable of amplifying an input signal with use of a low source voltage. Ordinarily, the amount of electrons released from a cathode which is heated by a heater is small since a voltage supplied to the heater is low. In the vacuum tube circuit disclosed here, a positive voltage is supplied to a grid terminal, which more effectively attracts the emitted electrons, thereby increasing the amount of electrons arriving at the plate terminal passing through the grid. As a result, a grid current and a plate current flow in the vacuum tube circuit, which achieves an operation for amplifying an input signal from a signal source.