Abstract: A firing arrangement for an initiator (1) includes a capacitor (16), an arming arrangement (6, 11, 14) for charging the capacitor (16) on receipt of an arming instruction and a trigger device (13). When a trigger condition is achieved which indicates sufficient charge on the capacitor (16), a trigger signal is automatically generated by the trigger device (13) to trigger discharge of the capacitor (16) through the initiator (1) to activate the initiator (1). The trigger condition may be a predetermined time after receipt of the arming instruction.

Abstract: A vehicle disabling apparatus for remotely disabling a vehicle having an engine comprises a source (4) of high frequency energy for generating a high frequency signal and a modulator (1) for modulating the high frequency signal by applying an effects signals package. The effects signal package comprises a plurality of respective effects signals and each effects signal comprises a pulse train, the effects signals package being non-vehicle specific. An antenna (6) directs the effects signal package modulated signal at a remote vehicle to disrupt the vehicle engine by affecting the target vehicle engine management system.

Abstract: A transformer includes a primary winding; a secondary winding; a first electrostatic screen located between the primary winding and the secondary winding and most proximate to the primary winding; and a second electrostatic screen located between the primary winding and the secondary winding and most proximate to the secondary winding. The first electrostatic screen is electrically connectable to a power supply electrically connectable to the primary winding and the second electrostatic screen is electrically connectable to a load electrically connectable to the secondary winding. The invention also includes an inverter system including the transformer.

Abstract: A vehicle disabling apparatus for remotely disabling a vehicle having an engine comprises a source (4) of high frequency energy for generating a high frequency signal and a modulator (1) for modulating the high frequency signal by applying an effects signals package. The effects signal package comprises a plurality of respective effects signals and each effects signal comprises a pulse train, the effects signals package being non-vehicle specific. An antenna (6) directs the effects signal package modulated signal at a remote vehicle to disrupt the vehicle engine by affecting the target vehicle engine management system.

Abstract: A switching arrangement for applying voltage pulses across a load, comprising a plurality of capacitive elements (C1-C9) connected in series, and a first switch arrangement (S) connected to the series connection to apply voltage pulses to the load, and a second switch arrangement (S1, S2) connected to a capacitive element of the series connection, such that one of the capacitive elements (C1) can be switched out of or switched into the series connection, in order to produce voltage pulses of respectively lower or higher levels, without the need to dissipate energy into a resistive load.

Abstract: A combining arrangement comprises a power combiner having at least four ports. A first match-dependent oscillator is connected to input power at a first frequency to a first input port of the power combiner. A second match-dependent oscillator is connected to input power at a second frequency to a second input port of the power combiner. A mismatch is connected to a third port of the power combiner. The power combiner is operative to combine power from the first and second oscillators and, when the first and second frequencies are different, to apply a fraction of the combined power to the mismatch. The mismatch reflects at least some of the fraction of the combined power to the first and second oscillators to phase and frequency lock their outputs. A fourth output port of the power combiner is connected to receive the combined power.

Abstract: A low-filter is arranged for attachment to an exterior face of a wall of an electrically conducting screened chamber encasing the magnetron and an associated isolation transformer electrically connected to terminals of the magnetron. Output connections of the filter pass directly through an interface between the electrically conducting screened chamber and the filter to connect electrically, directly or indirectly, with the isolation transformer. There are therefore no electrical leads outside the screened chamber electrically connecting the filter to the isolation transformer.

Abstract: A detector for determining the location of a pulsed laser spot reflected from a scene, which comprises a CCD sensor for imaging the scene comprising an array of pixels arranged in rows (R1, R2, R3) and columns (C1, C2, C3), a serial read-out register arrangement (not shown), and charge transfer electrodes (Ø1H, Ø1V, Ø2) capable of transferring signal charge in at least two adjacent pixels to read-out register arrangement locations representative of the row location of at least one of the adjacent pixels and the column location of at least one other of the adjacent pixels. The charge transfer electrodes are two phase, but three or more phase arrangements are also possible.

Abstract: Drive circuit and method for a gated semiconductor switching device A drive circuit and method for a gated semiconductor switching device (10) comprising providing coupling such as a mutual inductance between a gate drive circuit (21) for the device and a drain to source current supply circuit (22) for the device in order to change a gate voltage provided by the gate drive circuit dependent on a rate of change of a current in the drain to source current supply circuit. The change in gate voltage has a magnitude and phase arranged to increase or decrease a switching speed of the gated semiconductor switching device.

Abstract: A cathode of a magnetron having a radial extension to accommodate the cathode terminals is supported by arms which have a greater diameter over the region in which they are supported in the glass thimble than over the region of the free ends. This shifts any vibrations to a higher frequency band, which is less liable to be excited in the event the magnetron is moved rapidly as in a linac used for radiotherapy purposes.

Abstract: A magnetron has an anode body (1) and including a ceramic sleeve (7). In higher power generators, stray radiation is emitted from this sleeve in addition to the main power launched from the antenna into the waveguide (2), and RF absorbing material is provided. Such absorbers, however, tend to be frequency-selective, and can overheat. According to the invention, a non-metallic jacket (13) containing a dielectric liquid such as water surrounds the sleeve. This provides absorption over a broad band of frequencies, and it is easy to make the jacket have a sufficiently high thermal capacity, for example, by arranging a flow of liquid through it.

Abstract: A magnetron cathode comprises electron emissive material included in a cathode body and a support structure for supporting the cathode body. The support structure has a longitudinal axis and includes a first part having a first cylinder integrally formed with a first end hat and a second part having a second cylinder integrally formed with a second end hat. The first cylinder and the second cylinder have an overlapping region in the longitudinal axial direction and are joined together. The cathode body is located around the first cylinder of the first part of the support structure and is joined to the first cylinder by a brazed joint. The outer surface of the first cylinder is grooved at the brazed joint.

Abstract: A CMOS image sensor 101 comprises an active layer 11 of a first conductivity type arranged to be reversed biased and a pixel 20 comprising a photosensitive element comprising a well 22 of a second conductivity type and a well 21 of the first conductivity type containing active CMOS elements for reading and resetting the photosensitive element. The CMOS image sensor further comprises a doped buried layer 111 of the second conductivity type in the active layer beneath the well of the first conductivity type. The buried layer is arranged to extend a depletion region below the well of the second conductivity type also below the well of the first conductivity type.

Abstract: An inductive filter for a magnetron power supply lead comprises an electrically insulating tube; a power lead located partially within the electrically insulating tube, and coaxial therewith, for supplying power from a magnetron power supply to a magnetron, a first core of a first magnetic material and a second core of a second magnetic material coaxially located on the electrically insulating tube; an insulating disc of same external diameter as the first core and the second core and coaxially located on the electrically insulating tube between the first core and the second core. The inductive filter is arranged to filter noise of a first frequency band and noise of a second, different, frequency band different from being transmitted along the power lead and to absorb a predetermined transient voltage from being transmitted along the power lead.

Abstract: A high frequency cathode heater supply for a microwave source includes a SMPS inverter and an isolation transformer having a primary winding arranged to be powered by the SMPS inverter, a monitor winding passing through primary core assemblies of the primary winding and a secondary winding arranged for connection to the cathode heater. A current monitor is arranged to monitor a current in the primary windings. Signal processing modules are arranged to receive a first input signal from the monitor winding indicative of a voltage across the cathode heater and a second input signal from the current monitor indicative of a current through the cathode heater. The signal processing modules are arranged to output a control signal to the SMPS inverter to control power supplied to the cathode heater dependent on a monitored resistance of, or monitored power supplied to, the cathode heater as determined from the first input signal and the second input signal.

Abstract: A low-filter is arranged for attachment to an exterior face of a wall of an electrically conducting screened chamber encasing the magnetron and an associated isolation transformer electrically connected to terminals of the magnetron. Output connections of the filter pass directly through an interface between the electrically conducting screened chamber and the filter to connect electrically, directly or indirectly, with the isolation transformer. There are therefore no electrical leads outside the screened chamber electrically connecting the filter to the isolation transformer.

Abstract: A transformer comprises a primary winding 231; a secondary winding 233; a first electrostatic screen 234 located between the primary winding and the secondary winding and most proximate to the primary winding means; and a second electrostatic screen 235 located between the primary winding and the secondary winding means and most proximate to the secondary winding means. The first electrostatic screen is electrically connectable to a power supply electrically connectable to the primary winding and the second electrostatic screen is electrically connectable to a load electrically connectable to the secondary winding. The invention also includes an inverter system including the transformer.

Abstract: A magnetron has an anode and a cathode. The cathode includes two parts joined by sleeves of ferrous alloy spaced by a sleeve of insulating material. The ferrous alloy sleeves are adapted to be connected to opposite poles of a power supply for heating the cathode. A high frequency power supply is used to heat the cathode. The ferrous alloy sleeves have a surface coating of conductive material. The currents induced by the magnetic field generated by the high frequency currents of the power supply are largely confined to the conductive coating due to the skin effect, avoiding the heating of and losses in the ferrous alloy itself which would otherwise ensue.

Abstract: A magnetron cathode comprises electron emissive material included in a cathode body and a support structure for supporting the cathode body. The support structure has a longitudinal axis and includes a first part having a first cylinder integrally formed with a first end hat and a second part having a second cylinder integrally formed with a second end hat. The first cylinder and the second cylinder have an overlapping region in the longitudinal axial direction and are joined together. The cathode body is located around the first cylinder of the first part of the support structure and is joined to the first cylinder by a brazed joint. The outer surface of the first cylinder is grooved at the brazed joint.

Abstract: Drive circuit and method for a gated semiconductor switching device A drive circuit and method for a gated semiconductor switching device (10) comprising providing coupling such as a mutual inductance between a gate drive circuit (21) for the device and a drain to source current supply circuit (22) for the device in order to change a gate voltage provided by the gate drive circuit dependent on a rate of change of a current in the drain to source current supply circuit. The change in gate voltage has a magnitude and phase arranged to increase or decrease a switching speed of the gated semiconductor switching device.