As shown in the summary in Table 9, interference to the 3 representative types of integrated circuits can be expected at the center of the rectenna and at field as low as 1 mw/cm2 . However, interference is not expected at locations beyond 5.7 km from the center or in field of 0.1 mw/cm2 and weaker. Shielding with a shielding effectiveness of -40 dB should effectively eliminate interferences at all locations. 6. CONCLUSIONS This study has briefly assessed the circumstances under which interference might be expected between the solar power satellite and general electronics equipment. The study includes devices such as TV receivers, AM/FM receivers, electronic calculators, handheld transceivers, and cable TV components. Also examined were medical electronic devices with specific emphasis on pacemakers and site security devices such as proximity detectors and TV security cameras. Generally, the study has found very little experimental data in this subject area. Many of the following conclusions are based on interference studies by the Georgia Institute of Technology at frequencies of 420 to 450 MHz and 3.1 to 3.5 GHz. Even though these frequencies are different than the 2.45 GHz proposed for SPS, they do provide a valuable insight into the interference thresholds that might be expected. Interference threshold, as defined here, is the field intensities where some undesirable interaction is first noted. On the average, most of the equipment had interference thresholds in microwave fields of 10-2 mw/cm2 or greater. Exceptions to this were television receivers, under specific circumstances, and FM/FM stereo receivers. The circumstances that caused television receivers to have significantly lower interference thresholds were that, in some instances, the interference frequency was a spurious response of certain TV frequencies. The average interference threshold during those instances was 8 x 10 $ mw/cm2 . In contrast, the average interference threshold for those tests when there was no spurious relationship was 3 x 10-1 mw/cm2 . A mathematical analysis of the problem showed that the television channels that are most likely to be spuriously related to the SPS frequency is VHF channel 8, and UHF channels 28 and 29. Average interference thresholds for FM/FM stereo receivers were 5 x 10-3 mw/cm2 . While the cause for this slightly lower threshold is not known, there was no reason to suspect that these lower thresholds were caused by spurious responses. Some improvements in interference susceptibility in receivers could be obtained by improving the shielding effectiveness of the receiver cabinets, increasing the power line filtering, and by filtering and shielding the signal input leads. These improvements were typically of the order of 2 to 17 dB,
RkJQdWJsaXNoZXIy MTU5NjU0Mg==