Abstract:
A resonant cavity with a bowtie shape supports an electromagnetic field used to deflect the trajectory of an electron beam passing through the cavity. The short transit time of the beam across the gap maintains the cavity fields at near-optimal phase, improving interaction efficiency even for relatively low-energy beams. High interaction impedance ensures good drive-power-to-deflection conversion efficiency. The uniform field achieved across the gap enforces uniform deflection across the beam profile to maintain beam quality. Multiple bowtie cavities can be arranged to allow arbitrary two-dimensional deflections.
Abstract:
A device is proposed for producing high-frequency microwaves, having a cathode arrangement with heatable cathodes for emitting electrons, two grating arrangements for controlling and focusing the electrons flow and an anode for recaiving the electrons passing through the grating arrangements. The cathode arrangement and the first grating arrangement and also a blocking or choke element define an output cavity forming a resonance cavity and the anode and the second grating arrangement define an output cavity likeeise forming a resonance cavity. The cathode arrangement has a monuting for the cathode such that deformation of the cathode with reduction of the spacing between the heatable cathode and grating is avoided.
Abstract:
In a control grid for an electron tube, the grid has first bars that are evenly spaced out on a skewed surface and extend substantially as circle pseudo-involutes about a central hub.
Abstract:
The present invention pertains to an amplification device for a high-frequency signal. The invention is particularly adapted for the transmission of radiofrequency signals used for television of radio under frequency modulation. The amplification device for a high-frequency signal comprises of two amplification stages arranged in series, the first amplification stage being formed of a semiconductor preamplifier, the second amplification stage being formed of an electron tube cooled by the circulation of a fluid, the electron tube being arranged inside an enclosure intended to receive it. The semiconductor preamplifier is arranged in the enclosure and the preamplifier is cooled by the circulation of the fluid. The electron tube comprises a collector needing to be cooled by the circulation of the fluid, and the fluid circulates around a cooling circuit, in which the collector is connected in parallel with the preamplifier.
Abstract:
An inductive output tube (IOT) of a multi-staged depressed collector provides improved efficiency by approximating a Brillouin electron beam flow. In one embodiment, an IOT is provided with an electron gun that generates an electron beam, a tube body, a multi-staged depressed collector for collecting the electron beam, and a magnetic solenoid. The electron beam travels through the tube body. The magnetic solenoid produces a magnetic flux that focuses the electron beam as it travels through the tube body. The magnetic flux includes a portion that threads through the electron gun. The IOT is adapted to reduce this portion of the magnetic flux in order to provide improvements in the efficiency of the IOT.
Abstract:
An inductive output tube (IOT) of a multi-staged depressed collector provides improved efficiency by approximating a Brillouin electron beam flow. In one embodiment, an IOT is provided with an electron gun that generates an electron beam, a tube body, a multi-staged depressed collector for collecting the electron beam, and a magnetic solenoid. The electron beam travels through the tube body. The magnetic solenoid produces a magnetic flux that focuses the electron beam as it travels through the tube body. The magnetic flux includes a portion that threads through the electron gun. The IOT is adapted to reduce this portion of the magnetic flux in order to provide improvements in the efficiency of the IOT.
Abstract:
A linear amplifier comprises an electron gun assembly having a cathode, and an anode spaced from the cathode. A relatively high voltage potential is applied between the anode and the cathode, and the cathode provides an electron beam in response to the relatively high voltage potential. A control grid is spaced between the cathode and the anode, and is coupled to an input port adapted to receive the input signal. The input signal causes the control grid to density modulate the beam. The control grid is also coupled to a bias voltage source to preclude transmission of the electron beam during the negative half cycle of the input signal. A plurality of collector stages are provided with a respective electric potential thereto ranging between a potential of the cathode and a potential of the anode to efficiently collect the electrons of the beam after passing the anode. A first one of the collector stages is spaced from the anode opposite from the control grid and is further coupled to an output port to provide an amplified output signal therefrom. The respective electric potentials of the collector stages have corresponding voltage values such as to provide near-constant and high efficiency across a power range of the input signal.
Abstract:
A high efficiency linear amplifier comprises an electron gun assembly having a cathode and an anode, the cathode being operable at a relatively high voltage potential relative to the anode to form and accelerate an electron beam. A control grid is disposed between the cathode and the anode, and is biased relative to the cathode for Class B operation. A high frequency input signal is applied to the control grid to density modulate the electron beam. A shadow grid may be disposed between the control grid and the cathode. A drift tube encloses the beam and includes a first portion and a second portion with a gap defined between the first and second portions. An inductive output cavity communicates with the gap, and the density modulated electron beam passed across the gap and induces an RF electromagnetic signal into the cavity. A multistage depressed collector accepts and dissipates the electrons of the beam which remain after transit across the gap. Each of the collector stages have electric potential applied thereto ranging between ground and the cathode potential to efficiently collect the electrons. The electric potential can be specifically selected to preclude the collection of electrons at the beam potential, and maximize the efficiency of the amplifier.
Abstract:
The frequency of an AC signal is multiplied by a factor N, where N is an integer greater than one, by an electron tube including a cathode for emitting an electron beam and a grid including N segments in proximity to the cathode. The grid is biased and coupled to the signal so the beam is formed as N groups of electron bunches during each cycle of the signal. Each segment accelerates one group of bunches for a duration of about 1/N th of each cycle of the signal. Different groups of bunches associated with the different segments are accelerated at phases displaced from each other during each cycle of the signal. In response to the N groups of bunches an output signal having a frequency N times that of the signal is derived.
Abstract:
A method and an apparatus for enhancing modulation of a relativistic electron beam are described. A relativistic electron beam having been modulated is produced and passed through a superconducting passage having a periodicity in the passing direction of said beam. The periodicity is coincident with the modulation of the beam so that the modulation of the beam is enhanced by interaction between the beam and the superconducting passage through electromagnetic fields. The modulated electron beam can be used for generating microwaves at low power consumption.