18 research outputs found
Photoconductive switch applied to high power ultra-wideband unipolar and bipolar electrical pulse generation
International audienc
Ultra-wideband electrical pulse generator using photoconductive semiconductor switches
International audienc
Unipolar and bipolar electrical pulse generator using photoconductive semiconductor switches
International audienc
Ultra-Wide Band radar using optical synchronized photoconductive generators
International audienc
Small form factor 3D Printed UWB Antenna Based on Geopolymer Dielectric Material
International audienc
A Pulsed Modulator Combined With Very High PRF Photoconductive Switches to Build a Self-Scanning UWB Radiation Source
International audienceThe development and construction of self-scanning capability short-range ultrawideband (UWB) radar is forthcoming for the French Military for Defense. This paper is devoted to the presentation of the self-scanning radar principle and of the development, construction, and tests of the different blocks needed to implement the elementary part of the forthcoming radar. The elementary radiation source is composed of a microstrip line with photoconductive switches, an optical system to trigger the switches, a pulsed modulator used as bias voltage to load the line, and a UWB antenna to radiate high electric fields in a broad frequency band. The main proposed innovations are devoted to the integration of the photoconductive switches within the antenna and to the use of the pulsed modulator as bias source instead of a dc voltage source. This modulator allows considering the increase in the yield of the whole source as well as the increase in the radiation bandwidth. Experimental results are presented in order to compare the switching efficiency with a dc bias source against this pulsed modulator bias source. Finally, photoswitches triggered by an 80-ps/20-ÎĽJ laser source are able to generate monopolar or bipolar pulses in the kilovolt range with subnanosecond duration and a 33-MHz pulse repetition frequency. First radiated electric field results of the whole device are also reported. \textcopyright 2017 IEEE
Elaboration et caractérisation de matériaux géopolymères pour les antennes
International audienc