Abstract: A phased-array RF pulse generator is disclosed which includes a video-pulse generator arranged to generate video pulses each having a leading edge. An array of nonlinear and dispersive transmission lines, are arranged to generate RF pulses from the video pulses. At least one sensor is arranged to detect the leading edge of the video pulses after they have passed along the transmission lines. A phase controller is arranged to set the velocity of the video pulses in each transmission line to put the detected leading edges, and hence the generated RF pulses, into a desired phase relationship.

Abstract: A phased-array RF pulse generator is disclosed which includes a video-pulse generator arranged to generate video pulses each having a leading edge. An array of nonlinear and dispersive transmission lines, are arranged to generate RF pulses from the video pulses. At least one sensor is arranged to detect the leading edge of the video pulses after they have passed along the transmission lines. A phase controller is arranged to set the velocity of the video pulses in each transmission line to put the detected leading edges, and hence the generated RF pulses, into a desired phase relationship.

Abstract: A device for generating high powered Radio Frequency (RF) or microwave signals comprising a fast rise-time video pulse generator, a modulator to modify the generated UWB pulses by gyromagnetic action to transfer a portion of the UWB pulse energy from lower frequencies to frequencies in the RF or microwave range thereby producing a resultant RF or microwave waveform that can be radiated.

Abstract: A device for generating high powered Radio Frequency (RF) or microwave signals comprising a fast rise-time video pulse generator, a modulator to modify the generated UWB pulses by gyromagnetic action to transfer a portion of the UWB pulse energy from lower frequencies to frequencies in the RF or microwave range thereby producing a resultant RF or microwave waveform that can be radiated.

Abstract: A non-linear dispersive transmission line assembly for producing high power radio frequency electrical signals includes a transmission line (6, 7) having a plurality of series connected inductors (8) each incorporating saturable magnetic material to provide non-linearity, a first array (11) of capacitors interconnecting outermost ends of immediately adjacent pairs of the inductors (8) and a secondary array (14) of capacitors interconnecting outermost ends of immediately adjacent pairs of the inductors, with the second array interconnection points being spaced by one inductor from the first array interconnection points. The assembly also includes means for applying a first magnetic field to the transmission line (6,7) in a direction substantially perspectively to the direction of a second magnetic field produced in the transmission line by the application thereto of a high voltage input pulse which propagates through the transmission line to form an output high power radio frequency electrical signal.

Abstract: A phased array radio frequency pulse generator includes a plurality of radio frequency pulse generator units (4, 4a, 4b, 4c) each having a non-linear dispersive electrical circuit (1) incorporating at least one non-linear element (5) including a material sensitive to low power signals (7) and a means (6) for producing a variable power control signal (7) and applying it to be at least one non-linear element (5) to modify the extent of the non-linearity of the element and thereby vary the timing of the radio frequency electrical output signal generated, and means (13) for adjusting the value of the control signals (7) provided in each unit (4, 4a, 4b, 4c), to vary the relative phases of the output signals from the units (4, 4a, 4b, 4c) in a phased array on a pulse to pulse basis.

Abstract: A device for generating high powered Radio Frequency (RF) or microwave signals comprising a fast rise-time video pulse generator, a modulator to modify the generated UWB pulses by gyromagnetic action to transfer a portion of the UWB pulse energy from lower frequencies to frequencies in the RF or microwave range thereby producing a resultant RF or microwave waveform that can be radiated.

Abstract: A non-linear dispersive pulse generator for producing pulsed radio frequency electrical signals includes a non-linear dispersive electrical circuit (1) incorporating at least one non-linear element (2) made of a material sensitive to low power signals and a means (5) of producing a variable power control signal (6) and applying it to the element (2) to modify the extent of the non linearity of the element (2) and thereby vary the output frequency of the radio frequency electrical signal generated by the generator.

Abstract: This invention relates to periodic electromagnetic structures (20) for use over a relatively large range of frequencies. In particular, this invention relates to microwave applications, such as antennas and low reflectivity structures. A periodic electromagnetic structure (20) is provided that comprises an array of conducting LC elements (22;22a,22b;42;52;68) in superposition with a frequency-dependent dielectric (30;44;54;70) whose permittivity and/or permeability varies according to the frequency of radiation incident thereon such that the resonant frequency of the LC elements (22;22a,22b;42;52;68) follows the frequency of the incident radiation.

Abstract: A non-linear dispersive transmission line includes a plurality of substantially block-like shaped capacitor elements (4) arranged in sequence in at least two arrays. The even numbered elements (4b, 4d etc) extend side by side to form a first array and the odd numbered elements (4a, 4c) etc extend side by side to form the second array. Each element (4) in one array is connected via inductors (3) to two immediately adjacent elements in the other array. Facing surfaces (5) of each two immediately adjacent elements (4a, 4c) in each array form cross link capacitors.

Abstract: In a pulse forming electrical circuit suitable for use with a gas discharge laser having continuously falling impedance, there is provided a saturable inductor operable to cause the output impedance of the circuitry to vary with the current drawn by the load thereby ensuring that the matching between the impedance of the circuitry and the load to be better than would be the case if the impedance of the circuitry were fixed.

Abstract: A gas laser comprises an optical cavity, a coaxial transmission line at least partially disposed in the optical cavity, a lasant gas disposed in the cavity, and means for transmitting at least one electrical pulse progressively along the transmission line to generate a travelling wave of ionization to pump the lasant gas.