Millimeter Wave Regulation IEEE EMC – DC/No. VA Mitchell Lazarus | January 31, 2012 Millimeter Wave Regulation IEEE EMC – DC/No. VA Mitchell Lazarus | January 31, 2012 File copy provided by
Overview FCC restricted bands Communications GHz (unlicensed) GHz (unlicensed) 71-76, 81-86, GHz (licensed) Radar – Current Rules GHz GHz Radar – Waivers and Proposed Rules GHz GHz GHz 1 File copy provided by
Millimeter Wave Signals in General Advantages tight beams from small antennas can reuse same frequency nearby high data capacity Disadvantages need direct line-of-sight high free space attenuation high rain attenuation poor penetration of walls and terrain. 2 At X GHz, a one-foot antenna has a diameter of X wavelengths. File copy provided by
FCC Restricted Bands In the late 1980s, the FCC listed 64 “restricted bands”: closed to unlicensed transmitters range from 90 kHz to 36.5 GHz to protect sensitive receivers: – GPS, radio astronomy, satellite downlinks, air traffic radars, etc. FCC also declared all bands above 38.6 GHz to be “restricted” Authorizing unlicensed use above 38.6 GHz always requires removal from the restricted list part of the FCC rulemaking proceeding. 3 File copy provided by
Communications 4 File copy provided by
57-64 GHz (Unlicensed) – 1 Max average power 9 µW/cm² at 3 meters (40 dBm EIRP) max peak 500 mW Disadvantage: attenuation by O 2 molecules in atmosphere 5 WiGig Alliance: in-room data communications 1-6 Gbits/sec wireless HDMI, gaming, home storage network, etc. proposed IEEE ad. Frequency (GHz) Source: Adelia C. Valdez Va Tech –64 GHz 16 8 dB/km 0 File copy provided by
57-64 GHz (Unlicensed) – 2 Rulemaking proposal: average power 82 dBm EIRP minus 2 dB for every dB that antenna gain is below 51 dBi antenna must be outdoors or pointed outdoors Pending since June 2007 new rules possible in 2nd or 3rd quarter File copy provided by
92-95 GHz (Unlicensed) Coextensive with GHz licensed band (next slide) Max average power 9 µW/cm² at 3 meters (40 dBm EIRP) max peak 500 mW indoor only – minimizes interference to and from licensed users No FCC certifications issued to date. 7 File copy provided by
71-76, 81-86, GHz (Licensed) Each applicant receives a non-exclusive, nationwide license no limit on number issued For each link: electronic, real-time interference checks with Federal gov’t and non-gov’t incumbents interference cases are rare (except on certain rooftops) Max power 55 dBm EIRP No licensed use on GHz reserved for Federal research applications Minimum bit rate: 71-76, 81-86: bits/sec/Hz GHz: 1.0 bits/sec/Hz. 8 File copy provided by
Radar (Current Rules) 9 File copy provided by
57-64 GHz GHz fixed field disturbance sensors: max average power 9 µW/cm² at 3 meters (+40 dBm EIRP) peak power density 18 µW/cm² at 3 meters (+43 dBm EIRP) non-fixed or elsewhere in band: max peak power density 9 nW/cm 2 at 3 meters (+10 dBm EIRP) max peak transmitter output power 0.1 mW Unlicensed. 10 File copy provided by
76-77 GHz Vehicle-mounted radars only Unlicensed. Power limits: 11 Forward-Looking (dBm EIRP) Side- or Rear- Looking (dBm EIRP) Vehicle moving Vehicle stopped+23.5 File copy provided by
12 Radar (Waivers and Proposed Rules) File copy provided by
76-77 GHz (Proposed Rule) 100 watt (50 dBm) power limit regardless of direction; moving or stopped any application (not just vehicle-mounted) Pending since May File copy provided by
76-77 GHz (Waiver) Fixed use of 10 radars at Atlanta airport for tracking aircraft and vehicles on ground Must meet emissions limits for forward-looking, in-motion vehicle radars ( dBm EIRP) Granted September File copy provided by
77-81 GHz (Proposed Rule & Waiver) Use as in-tank level probing radars limited to commercial use at fixed locations Unlicensed Proposed emissions limits: +23 dBm EIRP average (measured with no tank wall) +43 dBm EIRP peak (measured with no tank wall) but pulse radars often have >20 dB P/A ratio –41.3 dBm EIRP (§15.209) (measured through metal or concrete) FCC acknowledges need to protect radio astronomy operations Pending since January 2010 Waiver granted pending rulemaking subject to above emissions limits. 15 File copy provided by
78-81 GHz (Proposed Rule & Waiver) Airport use to detect “foreign object debris” (FOD) on runways aircraft parts, tools, equipment and supplies, rocks, pavement fragments, luggage, wildlife FCC open to allowing other applications No proposal as to licensed vs. unlicensed No proposal as to power limits FCC acknowledges need to protect radio astronomy operations Pending since December 2011 Waiver granted pending rulemaking: airport FOD detection only 35 dBW EIRP license required. 16 File copy provided by
Conclusion Millimeter wave spectrum is the target of extensive engineering innovation FCC rules at 57 GHz and above are badly out of date FCC moving to update rules, but regulatory process is inherently slow. 17 File copy provided by
18 Thank you! Mitchell Lazarus | File copy provided by