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The complete text referenced here can be accessed at:
http://eznec.com/misc/food_for_thought/ The first one is "Forward and reverse power" and is much easier to read if it is copied-and-pasted into Word. The first comment is just a nit: "(the current isn't transformed by the half wavelength line either.)" A 1/2 wavelength of transmission line reverses the phase of the current, certainly a 180 degree "transformation". The main point centers around this false statement: "While the nature of the voltage and current waves when encountering an impedance discontinuity is well understood, we're lacking a model of what happens to this "reverse power" we've calculated." Absolutely false! We are not lacking a model. We have time- tested models that people with closed minds simply refuse to consider. One such model is the s-parameter analysis presented in HP's App Note 95-1, available on the web. Quoting: "Another advantage of s-parameters springs from the simple relationship between the variables a1, a2, b1, and b2, and various *POWER WAVES*. ... s-parameters are simply related to power gain and mismatch loss, quantities which are often of more interest than the corresponding voltage functions." (emphasis mine) The model is there. Concrete brains refuse to take a look and instead call it "gobbledegook" (sic). There's another model that agrees 100% with an s-parameter analysis and it is from the field of optics, covered in detail in _Optics_, by Hecht. Non-glare glass works the same way as a 1/4WL matching section in a transmission line. Again the model is there, just ignored by gurus on this newsgroup which leads to demonstrably wrong conclusions on their parts. What happens to the energy in EM light waves has been known and understood for many decades and cannot be understood without an understanding of the laws of physics governing interference between EM waves. Likewise, what happens to the energy in EM RF waves cannot be understood without an understanding of those same laws of physics. There are many posters to r.r.a.a who have no clue about the laws of physics governing interference between EM waves. That ignorance is the entire problem with this discussion. Solution: Alleviate the ignorance. Quoting again from Roy's web page: 'ANY MODEL PRESENTED TO ACCOUNT FOR WHAT HAPPENS TO "FORWARD" AND "REVERSE" POWER AT TRANSMISSION LINE ENDS HAD BETTER GIVE RESULTS THAT AGREE WITH THE ABOVE TABLE.' And, of course, the two above power/energy models agree exactly with Roy's table but that doesn't seem to matter one iota. They are still "gobbledegook" (still sic). -- 73, Cecil, http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
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