8results about "Amplifiers with tubes" patented technology

A valve amplifier (105, 305) comprising an output transformer (110, 310) and a capacitor (210, 410) connected in parallel with a secondary winding (205, 405) of the output transformer (110, 310) Systems (100, 300), methods, and valve amplifier accessories (325, 500, 600) are also provided.

A multi-voltage power generation circuit is disclosed. More specifically, the multi-voltage generation circuit includes multiple voltage modulation circuits that are configured to generate and maintain multiple modulated voltages. In a non-limiting example, the multiple modulated voltages can be used for amplifying multiple radio frequency (RF) signals concurrently. Contrary to using multiple direct-current (DC) to DC (DC-DC) converters for generating the multiple modulated voltages, the voltage modulation circuits are configured to share a single current modulation circuit based on time-division. By sharing a single current modulation circuit among the multiple voltage modulation circuits, it is possible to concurrently support multiple load circuits (e.g., power amplifier circuits) with significantly reduced footprint.

A valve amplifier (105, figure 1) having an output transformer (110, figure 1) and a capacitor 210 connected in parallel with secondary windings 205 of the transformer. A method of connecting a capaci

Methods and apparatus for amplifying an input RF signal according to at least two gain states are described. According to one aspect, a multi-gain amplifier circuit including a low noise amplifier having a stack of transistors is used to amplify an input RF signal. When switching from a low gain state to a high gain state, the drain-source voltage of the output transistor of the stack is increased to affect the operating region of the output transistor, thereby reducing nonlinearity at the output of the amplifier. When switching from a high gain state to a low gain state, the drain-source voltage of the input transistor of the stack is increased to affect the operating region of the input transistor, thereby reducing nonlinearity at the output of the amplifier.

An amplifying circuit includes a floating inverter amplifier and a voltage generating circuit. A threshold voltage of transistors in the floating inverter amplifier varies corresponding to an environmental condition. The voltage generating circuit is coupled with the floating inverter amplifier. The voltage generating circuit is configured to provide an operating voltage to the floating inverter amplifier. The operating voltage provided by the voltage generating circuit is linearly correlated to the threshold voltage, and the voltage generating circuit modulates a variation of the operating voltage to keep track with a variation of the threshold voltage.

The invention discloses an electron tube distribution parameter compensation method and device and a digital exciter, and relates to the technical field of short-wave communication, and the method comprises the steps: building a radio frequency input mathematical model of the feedback effect of a high-end electron tube screen electrode on a grid electrode, and obtaining an excitation signal based on electron tube interelectrode capacitance distribution parameter and excitation signal characteristics; obtaining a complex expression for describing a screen pole total input signal; calculating and generating a compensation reference signal which is in real-time phase synchronization with the radio frequency input signal; decomposing the compensation reference signal into an in-phase component and an orthogonal component, inputting the in-phase component and the orthogonal component into a digital exciter, and determining an additional phase modulation angle and an additional amplitude generated by feedback of an electron tube; reversely adjusting the phase and the amplitude of the DRM excitation signal according to the additional phase modulation angle and the additional amplitude, and outputting a phase modulation carrier for pre-compensating phase deviation in combination with a direct digital frequency synthesizer so as to realize electron tube distribution parameter compensation; the efficiency and stability of electron tube distribution parameter compensation can be improved.

This application discloses a method, apparatus, and digital exciter for compensating distributed parameters of a vacuum tube, relating to the field of shortwave communication technology. The method includes establishing a mathematical model of the radio frequency input of the plate-to-gate feedback effect of a high-end vacuum tube; obtaining a complex expression describing the total plate input signal based on the distributed parameters of the inter-electrode capacitance of the vacuum tube and the characteristics of the excitation signal; calculating and generating a compensation reference signal that is in real-time phase synchronized with the radio frequency input signal; decomposing the compensation reference signal into in-phase and quadrature components and inputting them into the digital exciter to determine the additional phase modulation angle and additional amplitude generated by the vacuum tube feedback; adjusting the phase and amplitude of the DRM excitation signal in reverse according to the additional phase modulation angle and additional amplitude, and combining it with a direct digital frequency synthesizer to output a pre-compensated phase deviation phase-modulated carrier to achieve vacuum tube distributed parameter compensation; this application can improve the efficiency and stability of vacuum tube distributed parameter compensation.

Methods and devices for amplifying an input RF signal according to at least two gain-states is described. According to one aspect, a multi gain amplifier circuit including a low noise amplifier having a stack of transistors is used for amplification of the input RF signal. When switching from a low gain-state to a high gain-state, the drain-to-source voltage of the output transistor of the stack is increased to affect region of operation of the output transistor, and thereby reduce non-linearity at the output of the amplifier. When switching from the high gain-state to the low gain-state, the drain-to-source voltage of the input transistor of the stack is increased to affect region of operation of the input transistor, and thereby reduce non-linearity at the output of the amplifier.