摘要:
An electronically controlled frequency agile impulse source utilizing pulse sharpening techniques to increase its versatility in radiating impulse energy at a variety of center frequencies and bandwidths in the megahertz to the gigahertz range. Such pulse sharpening provides for a radiator having a wider range of applications.
摘要:
The combination of a photoconductive switch coupled to an energy storage ice wherein the switch is comprised of photoconductive semiconductor material while the energy storage device comprises a radio transmission line including a different material, i.e. a dielectric storage medium. A photoconductive semiconductor gallium arsenide switch is embedded in a circular disc of dielectric material with upper and lower layers of continuous radial metallization configured in a circular pattern located thereon. The upper layer of metallization includes an apertured grid adjacent one surface of the switch, while the outer conductor of a coaxial output signal line is connected to the metallization layer on the opposite side with the inner conductor thereof passing through the dielectric layer to the undersurface of the semiconductor switch. A variation comprises the upper and lower metallization layers being formed in the shape of a plurality of discrete straight line segments or strips which extend radially outward from the center and thus forms a quasi-radial structure.
摘要:
A pulse forming network with distributed inductance and capacitance is diosed for use in a magnetic modulator. The magnetic modulator has a magnetic core with a primary winding and a secondary winding around it. The pulse forming network includes an inner winding of flattened wire around the magnetic core and connected to one end of the secondary winding for receiving an induced voltage. The pulse forming network also includes a metal foil shield around the inner winding, so that the induced voltage may be stored capacitively between the inner winding and the shield. When the magnetic core saturates, the impedance of the secondary winding drops, so that the pulse forming network discharges through a load. The shape of the pulse through the load is determined by the inductance of the inner winding and the capacitance between the inner winding and the shield. The number of turns per unit length of the inner winding, the spacing between the inner winding and the shield, and the dielectric constant of an insulating layer of material between the inner winding and the shield may all be modified to obtain a pulse forming network forming a desired pulse shape.
摘要:
Utilizing sections of charged transmission line cables and optically-actied semiconductor switches, the direct generation of high power RF is demonstrated.
摘要:
A photoconductive switch coupled to an energy storage device wherein the tch is comprised of photoconductive semiconductor material while the energy storage device comprises two spiral metalized arms that make up a spiral antenna. The photoconductive switch is electrically connected to the storage device to facilitate fast discharge of the stored energy through a load. A variation comprises a storage device comprising two separate pieces of substrate material each having a spiral metalized arm. The separate pieces being connected by highly dielectric material to form a spiral antenna ultra wideband radiator.
摘要:
A photoconductive ultra-wideband impulse generating device utilizing pulseharpening techniques to further increase its radiation frequency well above the gigahertz range while also substantially improving radiation efficiency. Such pulse sharpening provides for a radiator having a wider range of applications.
摘要:
A monolithic photoconductive pulsar utilizing a radial transmission line structure to store energy and a unique optical pulse illumination means to trigger the radial transmission line to radiate extremely, high voltage gain, narrow bipolar pulses. By achieving a higher voltage gain, the bipolar RF pulses are desirable in that they substantially improve the efficiency and lifetime of the device over the prior art.
摘要:
A photoconductive switch coupled to an energy storage device wherein the tch is comprised of photoconductive semiconductor material while the energy storage device comprises two discrete dielectric mediums. Each medium having a conductive electrode on the top and bottom surfaces to essentially form parallel capacitors wherein the parallel capacitors are separated by a predetermined gap distance. A photoconductive switch electrically connected to each medium such that the switches are located on the opposite sides of their respective mediums. The predetermined gap distance (between the electrodes) and the photoconductive switches (on opposite sides of the storage devices) provide suppression of surface flashover between very high voltage, charged electrodes. Such flashover suppression allowing for very high power pulse generation.
摘要:
Bulk gallium arsenide having a high hold-off voltage is optically activated by a laser resulting in high power output. A high voltage input is applied to a semi-insulating gallium arsenide material. The gallium arsenide material is activated by laser light, thereby resulting in large current conduction. An external oscillating signal is superimposed on the high current resulting in a high power output.
摘要:
A high voltage sub-nanosecond pulser and radiator including a radial transsion line consisting of a dielectric member sandwiched between two patterned layers of metallization, one of which comprises a plurality of radiating elements. A photoconductive semiconductor gallium arsenide switch is embedded in the dielectric member which has a constant thickness. The other layer of metallization includes an apertured grid adjacent one surface of the switch for application of an energization pulse of laser light.