Characteristics of microwave power absorption in an insect exposed to standing-wave fields

In the study of microwave biological effects, microwave irradiation experiments with pupae of insect (Tenebrio molitor) are performed actively. Experiments of this kind showed that the developmental anomalies produced by microwave irradiation on the pupae can not be explained simply by only the thermal effect. As a result, there has been considerable discussion on the nonthermal effects of microwaves. Among the many experiments, Olsen's 6-GHz band standing-wave irradiation experiment is noteworthy because it ignores the above nonthermal effects in that developmental anomalies depend only on the absorptive ability of the pupa. In a standing-wave experiment performed using the 2 GHz band, the result differed from that in the 6 GHz band. Thus we observed that the heating pattern distribution within a pupa is related to developmental anomalies. Using this prospective, this paper analyzes the absorbed power in a pupa exposed to microwave standing-wave electromagnetic fields and clarifies the characteristics of the absorbed power to the frequency as it relates to exposure locations. the results showed that a pupa can be exposed to an approximately uniform electromagnetic field separated into individual components of the fields in the 2 GHz band; however, this does not hold in the 6 Hz band. Moreover, distribution of heating potential (absorbed power per unit volume) within a pupa differs remarkably between the two frequency bands.