The convention for numbering harmonics is to use the order of the harmonic to which we refer. Four times a fundamental would be the fourth harmonic, for example. Thus, there is NO "first" harmonic.
In the frequency domain, a perfect square wave would contain no even harmonics. Digital designers often insist an emission at a second or fourth harmonic must be coming from some other part of the equipment under test, because THEIR clocks are all "square waves." In reality, there are no perfect square waves, and both even and odd harmonics will be found from just about everything. The wave form that contains no ODD harmonics is a sawtooth. Cortland ====================== Original Message Follows ==================== >> Date: 21-Apr-99 10:39:17 MsgID: 1067-104000 ToID: 72146,373 From: Scott Douglas >INTERNET:[email protected] Subj: Harmonics Chrg: $0.00 Imp: Norm Sens: Std Receipt: No Parts: 1 Hi All, Recently an interesting discussion came up about harmonics. A general disagreement followed. We hope you all can offer some insight and perhaps help us settle the question. The question is numbering of harmonics. One side says that given a fundamental frequency of 200 MHz, the first harmonic is 400 MHz, the second harmonic is 600 MHz and the third harmonic is 800 MHz. The other side says that given a fundamental frequency of 200 MHz, the first harmonic is 200 MHz (or same as fundamental), the second harmonic is 400 MHz and the third harmonic is 600 MHz. The other part of the discussion revolved around even and odd harmonics. One side says that even harmonics are lower amplitude than the odd harmonics, the other side says odd harmonics are lower amplitude than even harmonics. All discussions assumed non-sinusoidal sources, generally our sources are square- or modified-square waves. Can someone shed some light on harmonic numbering and if possible, point to a reference material that specifies this? Thanks in advance for your input. Regards, Scott [email protected] --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators). ====================== End of Original Message ===================== --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators).
