Abstract: A technique for radio transmitting data is described. As to a method aspect of the technique data to be transmitted to a receiver is represented by at least two partial modulation symbols. Each of the at least two partial modulation symbols is associated to a different layer of the radio transmission to the receiver. A modulation symbol is generated by combining the at least two partial modulation symbols at different power levels according to the associated layer. The modulation symbol is transmitted to the receiver.

Abstract: In a photomultiplier tube (PMT) device having a plurality of dynodes provided between a cathode and an anode, a cancellation circuit provides two different modulation signals to the PMT to cancel the effects of the modulation signals upon the output of the PMT. For one embodiment, a cancellation circuit includes an input to receive an input modulation signal, a first output to provide a first output modulation signal to a first dynode, and a second output to provide a second output modulation signal to a second dynode, wherein the first and second output modulation signals are 180 degrees out-of-phase. For another embodiment, the cancellation circuit provides the input modulation signal to one of the PMT's dynodes, and also subtracts the input modulation signal from the PMT's output signal.

Abstract: The invention relates to a method for extracting measuring signals from a multi-channel photomultiplier, characterised by the following steps: a measuring signal which is integral for the channels of the photomultiplier is extracted at the dynode in order to record the signal form and intensity of an event, and the anode signal of each channel is compared with a threshold value. If the threshold value is exceeded at a channel, the location of the detected event is determined and the associated signal form and intensity at the dynode is detected. The invention also relates to a circuit for a multi-channel photomultiplier (1), said circuit being used to carry out the method according to one of the claims 1 to 8. The circuit comprises a photocathode, a multi-channel structure for electron multiplication (dynode), and anodes (11) which are associated with the channels and are used for pixel-oriented charge amplification and collection.

Abstract: The invention relates to amplifying electron tubes operating at microwave frequencies. The electron tube comprises: a pump-out tube that allows the vacuum inside the electron tube to be created; an electron gun that emits an electron beam inside the electron tube; a collector that directly collects a first portion of the electron beam. The pump-out tube directly repels a second portion of the electron beam in the direction of the collector.

Abstract: A audio amplifier employs microchannel plate for multiplying input electrons to produce output electrons at a rate corresponding to an audio input signal. The MCP may have a segment input source, segmented input and output electrodes or a segmented anode for allowing independent amplification of multiple input channels.

Abstract: An electron amplifier and a method of manufacturing the same are provided. The electron amplifier includes a substrate in which a plurality of through holes are formed, a resistive layer deposited on the sidewalls of the through holes, an electron emissive layer including carbon nanotubes which is deposited on the resistive layer, and an electrode layer formed on each of the upper and lower sides of the substrate. Because the electron emissive layer of the electron amplifier is uniform and provides a high electron emission efficiency, the electron amplification efficiency is improved. The electron amplifier manufacturing method enables economical mass production of electron amplifiers.

Abstract: A cathode for a secondary emission structure comprised of a superconductive material is described. In one embodiment the cathode comprises a layer of a superconductive material such as yttrium barium cupric oxide, or rare earth substituted neodymium cupric oxides. The layer may be bonded to a metal electrode or preferably the cathode consist of a superconductive or conductive oxide. The use of a superconductive material provides a cathode having suitable secondary emission characteristics and, furthermore, which being conductive at room temperatures, as well as, temperatures of operation of the cathode, obviating the need for a use of a very thin film of a secondary emission material.

Abstract: A pulse generator for producing high-energy, subnanosecond electromagnetic pulses. The generator comprises a pulsed cathode assembly (160) which includes a microchannel-plate electron multiplier (150) triggered by a low-intensity, pulsed electron beam. An intense, pulsed electron beam obtained from the cathode assembly is directed through aperture (71) in waveguiding structure (170). It generates electromagnetic pulses, which are carried by the waveguiding structure to load (130).

Abstract: The present invention relates to a circuit for processing a signal received by an electron multiplier. The circuit comprises an electron multiplier followed by an electron collector, a power supply for the electron multiplier, a gain-compressing amplifier for processing the signal delivered by the electron collector, and a feedback path for continuously modulating the gain of the electron multiplier by means of a control circuit which acts on the HT power supply of the electron multiplier. This circuit is particularly suitable for use in mass spectrometry and in helium leak detection.

Abstract: The present invention discloses an enhanced secondary electron emitter cathode suitable for use in a typical crossed-field amplifiers. The emitter surfaces of the cathode are formed into protuberances or knurls. The cathode's secondary emission characteristics are enhanced by providing protuberances with more surface area for electrons to bombard and for electrons to be emitted from. The protuberances increase the variety of angles of incidence of bombarding electrons thereby increasing the probability that bombarded electrons can escape the cathode's surfaces.

Abstract: A crossed-field amplifier has a cathode in the form of a P-N junction semiconductor which is biased to the conductive state to cause the crossed-field amplifier to amplify. The P and N regions of the semiconductor are connected to an energy source which is pulsed to produce conduction in the P-N junction and thereby allow secondary emission from the cathode. A reverse bias voltage prevents secondary emission from the cathode. The tube requires only low voltages to be applied to the cathode P-N junction to completely deactivate the crossed-field amplifier tube without requiring the removal of the RF drive pulse applied to the cathode- or anode-slow-wave circuit and without requiring the removal of the DC high voltage power supply which therefore need not be pulsed.

Abstract: A dynode assembly having a given length and a field electrode assembly having the same given length are disposed in a vacuum envelope. The dynode assembly is in a first plane parallel to and spaced from the longitudinal axis of the envelope and the field electrode assembly is disposed in a second plane parallel to and spaced from the axis in a direction opposite to the spacing of the dynode assembly. The dynode assembly receives on its input end input electrons produced by an input signal which may be either electrical or optical. The field electrode assembly is shifted along the axis with respect to the dynode assembly such that the output end of the field electrode assembly extends beyond the output end of the dynode assembly such that lines of equal potential between the two assemblies form an angle .theta. with the first and second planes.

Abstract: A means is provided for reducing gain shifts in multiplier tubes due to varying event count rates. It includes means for limiting the number of cascaded, active dynodes of the multiplier tube to a predetermined number with the last of predetermined number of dynodes being the output terminal of the tube. This output is applied to an amplifier to make up for the gain sacrificed by not totally utilizing all available active stages of the tube. Further reduction is obtained by illuminating the predetermined number of dynodes with a light source of such intensity that noise appearing at the output dynode associated with the illumination is negligible.