5results 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.

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.