Be careful about using the antenna factor. The published antenna factor is a receive antenna factor, and for what you are trying to do you need the transmit antenna factor. You can calculate one from the other if you know the frequency, but they are not identical. I can provide that derivation. You should also know how the antenna factor was measured - if any attenuation was used to reduce vswr. Usually antennas will have vswr specified separately from antenna factor, which leads me to believe that quite a bit of attenuation is used to remove that source of error. Likely someone on this forum has direct experience calibrating antennas. All the factors you mentioned you can measure or get from a spec sheet, except chamber effects. I though the whole point of the chamber was to be anechoic enough to allow for that quiet zone calibration. That would mean to me there are no chamber effects.
---------- >From: [email protected] >To: [email protected] >Subject: Radiated Immunity Testing >Date: Thu, Sep 19, 2002, 7:11 AM > > > Using the antenna factor of a particular antenna, one can compute the > theoretical power required to create a specified E-field at a specified > distance. Without over specifying the power amplifier (assume Class A), what > minimum safety factor should be added to the theoretical values to account > for impedance mismatches, cable loss, directional coupler loss, compact > anechoic chamber effects (3 m) including loading of the antenna, the allowed > 6 dB field variation and any other effects. > > Richard Woods > Sensormatic Electronics > Tyco International > > > ------------------------------------------- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > [email protected] > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Ron Pickard: [email protected] > Dave Heald: [email protected] > > For policy questions, send mail to: > Richard Nute: [email protected] > Jim Bacher: [email protected] > > All emc-pstc postings are archived and searchable on the web at: > http://ieeepstc.mindcruiser.com/ > Click on "browse" and then "emc-pstc mailing list" > ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
