A microradio (10) is provided with a hysteretic switch (16) to permit an optimum range increasing charging cycle, with the charging cycle being long relative to the transmit cycle. Secondly, an ensemble of microradios permits an n2 power enhancement to increase range with coherent operation. Various multi-frequency techniques are used both for parasitic powering and to isolate powering and transmit cycle. Applications for microradios and specifically for ensembles of microradios include authentication, tracking, fluid flowing sensing, identification, terrain surveillance including crop health sensing and detection of improvised explosive devices, biohazard and containment breach detection, and biomedical applications including the use of microradios attached to molecular tags to destroy tagged cells when the microradios are activated. Microradio deployment includes the uses of paints or other coatings containing microradios, greases and aerosols.