Bob, This is a specific Japanese measurement procedure, defined in the Notice 88, appendix 43 from MIC. Consider also Article 49.20 from the Radio Ordinance.
1. The power density should be measured for each combination of Bluetooth mode (DH1, DH3, DH5 and modulation type (GFSK, 8DPSK and pi/4-DQPSK) and for the max. amount of channels and the minimum (If AFH is applicable). The max. amount is 79 and the minimum is normally 20. 2. You need to start with measuring the total transmit power - in fact without bandwidth limitation- with the sensor method. So in fact 18 possibilities normally for Bluetooth 2.0 + EDR. Result is P (mW) 3. Measure the "spreading" bandwidth, for both the max. amount of channels and the minimum (remaining channels clustered in the middle of the band, a worst-case assumption!) and for each modulation type (GFSK, 8DPSK and pi/4-DQPSK). The spreading bandwidth is the 90% power bandwidth. Sometimes it is indicated with the "diffusion" bandwidth. This bandwidth is considered as the "coverage" of the power P, which is the specific Japanese approach, resulting in an average density within the band Resulting Bandwidth is S (MHz) Normally it gives a value around 71 MHz (all 79 channels operational) and 17 MHz (with 20 channels clustered / operational) With the minimum amount of (clustered!) channels you get the smallest value for S. Consequently this situation results in the highest power density. 4. For each mode (DH1, DH3, DH5 etc) measure the duty-cycle. Result is D ( D <1) 5. Power density is defined by Pd (mW / MHz) = P / [D x S] since it is defined as the average power density within the transmit burst If you need more information, don't hesitate to contact me: Theo Hildering Product Assessor Certification Consultant QA documents for Testing and Certification Telefication bv CAB Japan for the certification of Radio Equipment and TTE to the Japanese requirements See www.telefication.com On 13-05-2008 16:44, "rehel...@mmm.com" <rehel...@mmm.com> wrote: > I am reading a Japanese standard for 2.4 GHz and it gives an "antenna > power" limit of 3mW/MHz (no antenna distance). Can someone help as to how > this is measured. I guess I don't understand the parameter being measured. > > Thanks > Bob Heller > 3M Company > St. Paul, MN 55107-1208 > Tel: 651- 778-6336 > Fax: 651-778-6252 > > - > ---------------------------------------------------------------- > This message is from the IEEE Product Safety Engineering Society > emc-pstc discussion list. Website: http://www.ieee-pses.org/ > > To post a message to the list, send your e-mail to emc-p...@ieee.org > > Instructions: http://listserv.ieee.org/request/user-guide.html > > List rules: http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > > Scott Douglas emcp...@ptcnh.net > Mike Cantwell mcantw...@ieee.org > > For policy questions, send mail to: > > Jim Bacher: j.bac...@ieee.org > David Heald: emc-p...@daveheald.com > > All emc-pstc postings are archived and searchable on the web at: > > http://www.ieeecommunities.org/emc-pstc Mozartlaan 4 45 6865GB Doorwerth, The Netherlands E-mail: h.hilder...@kpnplanet.nl Tel. +31 263790590 - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
