A Reconfigurable Transient Antenna Based on Shaped Charge Jet

In response to the demands for communication encryption and electromagnetic protection in modern military scenarios, a novel reconfigurable transient antenna has been designed using shaped charge. This antenna utilizes the shaped charge jet as the radiating element and a metal plate as the equivalent ground, with excitation provided by a coaxial line. A combined simulation approach (CST for electromagnetic analysis, Autodyn for explosive dynamics) validates its feasibility: the jet exhibits radiation characteristics similar to a planar monopole, and the explosive process confirms structural stability. Additionally, modal analysis reveals that the jet excites radiation modes where the jet acts as the primary radiating body. The reconfigurability is achieved through dynamic variation of jet length by stretching and adjusting the charge configuration, which modulates the impedance bandwidth and resonant frequency, with longer jets corresponding to lower frequencies. Equivalent physical models for the jets formed by charges with diameters of Ø30mm and Ø56mm were created, followed by measurement of return loss and radiation pattern The results indicate that the Ø30mm shaped charge jet antenna achieves a gain exceeding 2.2 dBi within the frequency range of 1.17-1.81 GHz, while the Ø56mm jet antenna offers a -10 dB impedance bandwidth covering 0.52-0.68 GHz with a peak gain of 4.5 dBi, exhibiting an omnidirectional radiation pattern. The findings of this study can address the miniaturization issue of low-frequency antennas used in EMP weapons.