That is definitely the way to deal with the issue. The receiver IF filter will definitely reject energy 500 kHz off the tuned frequency in a traditional superheterodyne receiver. I could still see the front end being desensitized, but it will take more harmonic energy to do that.
From: Bob Richards <[email protected]> List-Post: [email protected] Date: Tue, 13 Jun 2006 10:25:50 -0700 (PDT) To: [email protected] Subject: Re: RF Power Amplifiers I'm not familiar with the specific test requirements for receivers, but the 1000-4-3 spec allows step sizes of 1% of the fundamental. If not required to do otherwise, I would arrange the test frequencies so the subharmonic frequencies are avoided, IOW, instead of testing at 105 MHz, test at 104.5 and 105.5 MHz. I would think the selectivity of most receivers would reject these signals. Bob Richards, NCT. Ken Javor <[email protected]> wrote: A quick calculation will show that if an immunity requirement of 10 V/m is imposed at 105 MHz on a 420 MHz tuned receiver with a sensitivity of -100 dBm, the harmonic content at 420 MHz needs to be on the order of 100 dB down from the carrier. That is quite unrealistic even for a VHF source for which 420 MHz is out-of-band, let alone a broadband amplifier and antenna combination that covers (typically) 80 - 1000 MHz. - ---------------------------------------------------------------- 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 [email protected] 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] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc - ---------------------------------------------------------------- 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 [email protected] 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] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
