RF Shorts for Jan. 17, 2014

FCC Modifies 7 GHz BAS Band Tank Level Probing Radar Rules

The FCC released a Report and Order modifying Part 15 of its rules for level probing radars (LDRs) operating on an unlicensed basis in the 5925-7250 MHz, 24.05-29.00 GHz, and 75-85 GHz bands. The modifications revise the measurement procedures to provide more accurate and repeatable measurement protocols for these devices. These devices can be used outdoors to measure levels of such things as water basins and coal piles. They can also be used in tanks or other enclosures, in which case they are commonly referred to as a tank level probing radar (TLPR).

Under the new rules, for certification purposes emissions are measured in the main beam of the LPR antenna while taking into account the significant attenuation that occurs upon reflection of these emissions. Radiated emissions will still be limited to avoid interference to other services, including Broadcast Auxiliary Service links in the 7 GHz band.

For details on how the measurements are made and attenuation calculated, see Report and Order and Order (FCC 14-2).

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Doug Lung is one of America's foremost authorities on broadcast RF technology. He has been with NBC since 1985 and is currently vice president of broadcast technology for NBC/Telemundo stations.