Aperiodic active and semi-active high sensitivity, broad dynamic range electromagnetic sensors

In many instances, the sensitivity/band tradeoff is a major handicap for the passive NEMP (nuclear electromagnetic pulse) sensor. This handicap can be compensated for by using active sensor or semiactive design. By design, active electric field sensors use armatures similar to those used in NEMP passive sensors. These armatures form a capacitor when charged on a high impedance to produce a sensor that is sensitive not to derivation of the field but to the field itself. The combined utilization of the technologies discussed permits construction of sensing elements based on active sensor design whose performance approaches a bandwidth of 2 GHz and an instantaneous dynamic range of 140 dB with a sensitivity of 1 /spl mu/V/m//spl radic/Hz. The use of semiactive sensors yields a performance of over 10 GHz, even up to 30 GHz, with a measurement dynamic of 95 dB with a field of 100 V/m; sensitivity is then on the order of 1.7 mV/m//spl radic/Hz, i.e., 30 to 100 times greater than that for equivalent passive sensors.<
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