Yu. A. Andreev

Generation and emission of high-power ultrabroadband picosecond pulses

The generation and emission of high-power ultrabroadband electromagnetic pulses are studied. The possibility of high-voltage (about 100 kV) bipolar voltage pulses with a duration of about 200 ps is demonstrated. The electromagnetic pulses with a FWHM of less than 100 ps, an effective potential of up to 400 kV, and a repetition rate of 100 Hz are generated using the 16-element antenna array.

A source of high-power pulses of elliptically polarized ultrawideband radiation.

Here, we describe a source of high-power ultrawideband radiation with elliptical polarization. The source consisting of a monopolar pulse generator, a bipolar pulse former, and a helical antenna placed into a radioparent container may be used in tests for electromagnetic compatibility. In the source, the helical antenna with the number of turns N = 4 is excited with a high-voltage bipolar pulse. Preliminary, we examined helical antennas at a low-voltage source aiming to select an optimal N and to estimate a radiation center position and boundary of a far-field zone. Finally, characteristics of the source in the operating mode at a pulse repetition rate of 100 Hz are presented in the paper as well. Energy efficiency of the antenna is 0.75 at the axial ratio equal to 1.3. The effective potential of radiation of the source at the voltage amplitudes of the bipolar pulse generator equal to -175/+200 kV reaches 280 kV.

A high-performance source of high-power nanosecond ultrawideband radiation pulses

A source of high-power nanosecond ultrawideband electromagnetic pulses is described. The 3-ns-long bipolar voltage pulse with a 90-kV amplitude is applied to the input of four-element antenna array. The effective radiation potential values EpR = 560 kV were obtained at a 100-Hz pulse repetition rate.

Generation and radiation of high-power ultrawideband pulses with controlled spectrum

A pulsed source of the ultrawideband radiation based on a nonlinear line and a single combined antenna is proposed. The frequency that corresponds to the maximum radiation spectrum can be tuned in the interval 0.5–1.3 GHz. The effective radiation potential of the source is 95–310 kV.

High-power ultrawideband electromagnetic pulse source

The source of high-power ultrawideband (UWB) radiation based on single compact antenna excited with 1-ns bipolar pulse has been created. Antenna input pulse amplitude is up to 120-kV and pulse repetition rate up to 100 Hz. The antenna efficiency by peak power was 60%. The peak power of the source was 170 MW. The antenna pattern width by half-power is 100/spl deg/ for the H-plane and 105/spl deg/ for the E-plane. The efficient voltage of the source equal to product of the peak field strength and the distance made /spl sim/130 kV.

Gigawatt-power-level ultrawideband radiation generator

An ultrawideband electromagnetic radiation pulse generator of peak power up to 1.3 GW and pulse repetition rate of 100 Hz has been developed and investigated. The generator consists of a high-voltage source of 200-kV bipolar voltage pulses of /spl sim/3-ns duration and a four-element antenna array. To increase the electric strength, the antennas were placed in dielectric containers under the gauge pressure of SF/sub 6/ gas. The array efficiency by peak power was /spl les/50%. The width of the wave beam of vertically polarized radiation at the power half-level in two mutually perpendicular planes was about 45/spl deg/.

Electromagnetic radiation of a nanosecond discharge in an open gas-filled diode

The properties of the discharge in and radiation from an open gas-filled diode to which high-voltage nanosecond pulses are applied from the RADAN-220 generator are studied. Electromagnetic radiation in the X-ray, UV, visible, and near-IR ranges of the spectrum, as well as high-power subnanosecond (0.5-to 0.7-ns-long) pulses of ultra-wide-band (UWB) electromagnetic radiation, are recorded when a diffuse discharge is initiated in atmospheric pressure air. For the coaxial cathode and anode, the open gas diode emits radially polarized UWB pulses, whereas for the cathode in the form of a segment, the UWB radiation is linearly polarized. The effective potential for both designs of the diode is ER = 6 kV. It is shown that the plasma in the discharge gap serves as a source of soft X rays and the metallic anode generates hard X rays.

Combined antenna and linear arrays for radiation low-power picosecond pulses

A wire model and a combined antenna for radiation of low-power bipolar pulses with a duration of 200 ps, which is based on this model, are developed. The frequency-domain characteristics of the model and the time- and frequency-domain characteristics of the combined antenna are studied. Linear antenna arrays based on the developed combined antenna are designed and the radiation characteristics of these antennas in the wave-beam scanning mode are analyzed.

An ultrawideband Gigawatt pulse generator

An ultrawideband pulse generator consists of a bipolar voltage pulse generator, a four-channel power divider, and a flat (2×2) equally spaced equal-amplitude antenna array. Characteristics of the ultrawide-band radiation at the excitation of the antenna array by bipolar pulses with a±200-kV voltage amplitude, ≈3.5-ns duration, and 100-Hz pulse repetition rate are given. The peak power of the vertically polarized radiation is 1.3 GW.

Emission of High-Power Ultrawideband Elliptically Polarized Pulsed Radiation by a Cylindrical Helical Antenna

Ultrawideband elliptically polarized radiation is numerically and experimentally studied. The analysis is performed for the axial radiation of a cylindrical helical antenna that is excited by a bipolar voltage pulse with a duration of 2 ns. The results are used for construction of a source of high-power ultrawideband pulses with elliptical polarization. The radiation pulses with an effective potential of 300 kV are generated at an amplitude of the bipolar voltage pulse of 200 kV and a repetition rate of 100 Hz.