MEASUREMENT OF EQUIVALENT POWER-DENSITY AND RF ENERGY DEPOSITION IN THE IMMEDIATE VICINITY OF A 24-GHZ TRAFFIC RADAR ANTENNA

In response to reports of alleged health effects associated with the u se of hand-held traffic radars, e.g., testicular cancer, a study was u ndertaken to quantify: 1) The distribution of the electric field (E) i n the immediate vicinity of the antenna aperture of a typical 24-GHz h and-held traffic radar; and 2) the relative match and the correspondin g depth of penetration of the absorbed energy when the antenna apertur e is positioned in contact with material having properties similar to human tissue, The former measurements are important for assessing a la rge number of measurements reported by others [1]-[3] using techniques that are not expected to be reliable indicators of power density at d istances small compared with the size of the radiator; the tatter are important for verifying predictions that energy from the antenna at 24 -GHz will be predominantly absorbed in superficial tissue, i.e., the s kin, The results of the first part of the study indicate that the equi valent-plane-wave power density in the plane of the aperture of the ra dar antenna is approximately one-half of the corresponding values repo rted in the literature; the results of the second part of the study in dicate that the depth of penetration into material simulating human sk in is approximately 0.5 mm.