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In this paper, a high-power ultra-wideband radiation system, composed of multiply radiation modules, is developed based on the space-synthesis method. The radiation module mainly consists of a transistorized pulser, a 2 × 2 combined antenna array, and a power divider. To improve the out parameters [the amplitude, the pulse repetition frequency (PRF), and the rise time] of the transistorized pulser based on the Marx circuit, the influence of the traveling wave process on the output pulse must be concerned. Based on the theoretical analysis, the printed circuit board circuit parameters and the circuit structure of the pulser are optimized. To improve the power synthesis efficiency, the pulse jitter characteristic of the pulser is improved by replacing the conventional base triggering mode with the collector voltage ramp triggering mode for the first-stage avalanche transistor in the pulser. The previous optimized antenna array is utilized in this radiation system, which has a better radiation performance in the prescribed aperture area. In addition, based on the gradient microstrip structure, the power divider integrated with the pulser is designed, which has the advantages of wide bandwidth, low loss, and light weight. Experimental results show that the peak effective potential rEp of the radiation system of 20 radiation modules is 221.8 kV, the maximum PRF could reach 10 kHz, and the half-power radiation angles of its radiation field are about 5° in both the E plane and the H plane. More radiation modules could be integrated into the system to achieve a higher electric field in the future. [ABSTRACT FROM AUTHOR]

In this note, a portable ultrawideband (UWB) electromagnetic radiator is developed based on a transistorized pulser with the peak power of 1.4 MW, the rise time less than 150 ps, and the repetition frequency of 50 kHz. To generate high-amplitude pulses, a 100-stage Marx circuit with parallel connection of multiple transistors is proposed. To improve the pulse repetition rate, the parallel charging Marx circuit is adopted with ferrite beads connected in series between stages for high isolation of pulses. In order to radiate the UWB electromagnetic pulse directionally, a compact combined antenna array is fabricated and connected with the pulser via a coaxial feeding module. The effective potential of the UWB radiator reaches 10.5 kV with the band range (−10 dB) from 173 MHz to 2.32 GHz. [ABSTRACT FROM AUTHOR]