A Broad-Band Isotropic Real-Time Electric-Field Sensor (BIRES) Using Resistively Loaded Dipoles

A broad-band isotropic real-time electric-field sensor (BIRES) developed by the National Bureau of Standards (NBS) consits of three resistively loaded dipoles mounted orthogonally to each other. It has the capability of measuring a complete description of frequency, polarization, magnitude, and phase information of the incident eleoa i (EM) fild. The typical tangential sensitivity of the BIRES is 13 to 16 ¿V/m with a usable dynamic range of 125 to 144 dB for various bandwidths in the frequency range of 10 MHz to 1 GHz. The isotropic response, isotropy, of the BIRES is obtained by calculating the magnitude of the incident electric field, and its variation is found to be le than ± 1 dB.