Reconfigurable plasma antenna produced in air by laser-induced filaments: Passive radar application

A virtual reconfigurable plasma antenna consisting of a set of laser plasma filaments produced in air by the propagation of femtosecond laser pulses in air is investigated. Several possible configurations of such virtual antenna are introduced. Input impedance, radiation pattern and current distribution, thermal noise and the radiation efficiency of a laser-induced plasma antenna are calculated. Field properties of plasma and copper antennas are compared. The results show that the proposed antenna has severe success with wide band of frequencies, which gives it suitability for transmitting a diversed radar waveform with the passive radar applications. It gives the passive radar a great advantage in its ability for using a wide band diverse pulse train to improve the detection probability of the radar with stealthy fluctuated targets, which difficult to generate using the tradition antenna.