Long-Term Study of 435 MHz Radio-Frequency Radiation on Blood-Borne End Points in Cannulated Rats. Part I: Engineering Considerations

To study the effects of exposure to long-term, low-level radio-frequency radiation (RFR) on various physiological systems in a large population of rodents, a complete exposure facility was designed and constructed at the Georgia Institute of Technology. The major components of the facility included a set of circular, stacked, parallel-plate waveguides fed by slotted-cylinder antennas. The waveguides provided a TE10 mode, horizontally polarized field in which the maximal power density occurred midway between the parallel plates. The feed antenna and the parallel-plate waveguides generated a field that radiated outward and was uniform in the azimuthal plane. Thus, animals arrayed along the periphery of the plates were exposed to a uniform 1.0 mW/cm2 field (1.0 microsecond pulse width, 1 kHz pulse repetition rate, 435 MHz carrier). The facility transmitter provided four channels of 435 MHz RFR at 200 W average (continuous wave) or 5 kW peak (pulsed-wave) power; in addition, the transmitter outputs could be combined into a single channel capable of energizing one tier of the stacked parallel-plate waveguide system at 800 W continuous wave or at 16 kW of pulsed waves. To individually house the 200 rodents involved in the study, both biological and engineering criteria were examined and used to design and construct special Plexiglas cages.