You don’t say what receiver you are using, but the numbers you quote imply a nearly 50 dB noise figure. That seems high. That being said, proper pre-amplification can reduce the noise figure to approach 0 dB noise figure. Also, you can use an antenna with better antenna factor than the 3115. But be sure that the antenna factor is spec’d at the distance you will use thee antenna. A 20 dB SGH won’t yield that far field gain at one meter at 2 GHz. Ken Javor
Phone: (256) 650-5261 ________________________________ From: "ce-test, qualified testing bv - Gert Gremmen" <[email protected]> List-Post: [email protected] List-Post: [email protected] List-Post: [email protected] Date: Tue, 25 May 2010 21:17:28 +0200 To: <[email protected]> Conversation: Radiated emission testing for automotive at low levels. Subject: Radiated emission testing for automotive at low levels. Colleagues and friends, I have recently been asked to quote testing for automotive car manufacturers ESA specifications. Part of the specification is very low level testing, as low as 20 dBuv/m at 120 Khz BW above 1 Gig. Can any of you shine their lights/contribute 2 cents on the test configuration needed for that. I have run into the following problem: Our R&S analyzer has a noise floor at 120 kHz bandwidth of approximately -71 dBm. Adding a 6 dB preamplifier noise and 24 dB gain lowers the noise floor to 89 dBm (18 dBuV). Our horn antenna (3115) has a AF of >20 dB (@1m) and the resulting noise level field strength is about >38 dBuV/m What is your choice in solving this problem ? Gert Gremmen - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.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 <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher <[email protected]> David Heald <[email protected]> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.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 <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher <[email protected]> David Heald <[email protected]>
