*From*: "Beal, Weston" <Weston_Beal@xxxxxxxxxx>*To*: "haaeri@xxxxxxxxx" <haaeri@xxxxxxxxx>, "si-list@xxxxxxxxxxxxx" <si-list@xxxxxxxxxxxxx>*Date*: Mon, 9 Apr 2012 22:49:59 +0000

Characteristic impedance applies to propagating EM waves, so it does not apply to DC. Or, if you look at the general equation that you cited, you can see that when jw = 0, the impedance approaches the line resistance. Somewhere in college I remember seeing a graph of the general impedance equation compared to actual measurement at low frequency. They are the same above some kHz, but diverge as frequency decreases. Weston -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of mohammad haaeri Sent: Monday, April 09, 2012 3:31 PM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] characteristic impedance at DC Hi, What is the characteristic impedance of a transmission line at DC? If you are saying Z0=sqrt(Rdc/Gdc) at DC, since Gdc=0, and Rdc is not zero, therefore Z0 is infinite. Is it correct? How does behavior of L, R, G, and C (line parameters) change vs. frequency (at low and DC, and at very high frequency)? Can Z0=sqrt(R+jwl/G+jwc) be used for all frequencies? Thanks, mohammad ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: http://www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List forum is accessible at: http://tech.groups.yahoo.com/group/si-list List archives are viewable at: http://www.freelists.org/archives/si-list Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: http://www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List forum is accessible at: http://tech.groups.yahoo.com/group/si-list List archives are viewable at: http://www.freelists.org/archives/si-list Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu

**Follow-Ups**:**[SI-LIST] Re: characteristic impedance at DC***From:*Nick Luther

**References**:**[SI-LIST] characteristic impedance at DC***From:*mohammad haaeri

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- » [SI-LIST] Re: characteristic impedance at DC - Todd Westerhoff
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- » [SI-LIST] Re: characteristic impedance at DC - Nick Luther
- » [SI-LIST] Re: characteristic impedance at DC - mohammad haaeri
- » [SI-LIST] Re: characteristic impedance at DC - Nick Luther
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- » [SI-LIST] Re: characteristic impedance at DC - Muranyi, Arpad
- » [SI-LIST] Re: characteristic impedance at DC - Muhammad Nazir
- » [SI-LIST] Re: characteristic impedance at DC - Brad Brim
- » [SI-LIST] Re: characteristic impedance at DC - Yuriy Shlepnev
- » [SI-LIST] Re: characteristic impedance at DC - Muranyi, Arpad
- » [SI-LIST] Re: characteristic impedance at DC - mohammad haaeri
- » [SI-LIST] Re: characteristic impedance at DC - Muranyi, Arpad
- » [SI-LIST] Re: characteristic impedance at DC - Kevin Rhoads
- » [SI-LIST] Re: characteristic impedance at DC - Antonis Orphanou
- » [SI-LIST] Re: characteristic impedance at DC - Luciano Boglione
- » [SI-LIST] Re: characteristic impedance at DC - steve weir
- » [SI-LIST] Re: characteristic impedance at DC - Howard Johnson
- » [SI-LIST] Re: characteristic impedance at DC - mohammad haaeri
- » [SI-LIST] Re: characteristic impedance at DC - Oh, Dan
- » [SI-LIST] Re: characteristic impedance at DC - Shawn Zheng
- » [SI-LIST] Re: characteristic impedance at DC - Todd Westerhoff
- » [SI-LIST] Re: characteristic impedance at DC - Todd Hubing
- » [SI-LIST] Re: characteristic impedance at DC - mohammad haaeri
- » [SI-LIST] Re: characteristic impedance at DC - Kevin Rhoads
- » [SI-LIST] Re: characteristic impedance at DC - Oh, Dan
- » [SI-LIST] Re: characteristic impedance at DC - Lee Ritchey
- » [SI-LIST] Re: characteristic impedance at DC - Antonis Orphanou
- » [SI-LIST] Re: characteristic impedance at DC - Antonis Orphanou