Could some electronics guru here please clarify this ? S{OCE AC analysis allows measurement of small signal s parameters. Using these measured values, the elements of the impedance matrix(Z matrix - Z11, Z12, Z21 and Z22) cam be calculated(messy but straightforward calculation, done easily with C code) Once the elements of the Z matrix have been calculated, the input, output impedances of the 2 port network can be calculated(as before messy but straightforward calculation, easily done with C code).
For an inductor operating at RF|microwave frequencies in the non-resonace frequency range, the quality factor is
(wL/R(f)) w -> angular frequency, L inductance(geometry based) and R(f)
the frequency dependent resistance. So, if one were to measure the Q factor of a microstrip rectangular inductor e.g., at 759 MHz, which of Z11, Z12, Z21 , Z22 Zin, Zout would be used to get the Q factor?
All hints|suggestions will be greatly appreciated. Thanks in advance.
Inductor Q factor calculation from SPICE AC analysis
Started by ●October 30, 2021
Reply by ●October 30, 20212021-10-30
On Saturday, October 30, 2021 at 5:34:59 PM UTC+11, daku...@gmail.com wrote:> Could some electronics guru here please clarify this ? S{OCE AC analysis allows measurement of small signal s parameters. Using these measured values, the elements of the impedance matrix(Z matrix - Z11, Z12, Z21 and Z22) cam be calculated(messy but straightforward calculation, done easily with C code) Once the elements of the Z matrix have been calculated, the input, output impedances of the 2 port network can be calculated(as before messy but straightforward calculation, easily done with C code). > For an inductor operating at RF|microwave frequencies in the non-resonant frequency range, the quality factor is > (wL/R(f)) w -> angular frequency, L inductance(geometry based) and R(f) > the frequency dependent resistance. So, if one were to measure the Q factor of a microstrip rectangular inductor e.g., at 759 MHz, which of Z11, Z12, Z21 , Z22 Zin, Zout would be used to get the Q factor? > All hints|suggestions will be greatly appreciated. Thanks in advance.The catch here is that the microstrip is a distributed inductance. The quality factor is for a lumped inductance. You might make more progress if you treated your microstrip as a series of transmission line elements. As is usual here, I'm going to point out that you might make more progress - and might even get some useful help - if you told us why you were making the measurement and what you wanted to do with the quality factor once you had extracted it. Most of this kind of stuff turns out to be somebody looking at a problem from the wrong point of view, and if the original poster backs up far enough somebody will recognise the problem and spell out the well-known approach that actually works. -- Bill Sloman, Sydney
Reply by ●October 30, 20212021-10-30
On Saturday, October 30, 2021 at 4:13:33 PM UTC+5:30, bill....@ieee.org wrote:> On Saturday, October 30, 2021 at 5:34:59 PM UTC+11, daku...@gmail.com wrote: > > Could some electronics guru here please clarify this ? S{OCE AC analysis allows measurement of small signal s parameters. Using these measured values, the elements of the impedance matrix(Z matrix - Z11, Z12, Z21 and Z22) cam be calculated(messy but straightforward calculation, done easily with C code) Once the elements of the Z matrix have been calculated, the input, output impedances of the 2 port network can be calculated(as before messy but straightforward calculation, easily done with C code). > > For an inductor operating at RF|microwave frequencies in the non-resonant frequency range, the quality factor is > > (wL/R(f)) w -> angular frequency, L inductance(geometry based) and R(f) > > the frequency dependent resistance. So, if one were to measure the Q factor of a microstrip rectangular inductor e.g., at 759 MHz, which of Z11, Z12, Z21 , Z22 Zin, Zout would be used to get the Q factor? > > All hints|suggestions will be greatly appreciated. Thanks in advance. > The catch here is that the microstrip is a distributed inductance. > > The quality factor is for a lumped inductance. You might make more progress if you treated your microstrip as a series of transmission line elements. > > As is usual here, I'm going to point out that you might make more progress - and might even get some useful help - if you told us why you were making the measurement and what you wanted to do with the quality factor once you had extracted it. > > Most of this kind of stuff turns out to be somebody looking at a problem from the wrong point of view, and if the original poster backs up far enough somebody will recognise the problem and spell out the well-known approach that actually works. > > -- > Bill Sloman, SydneyI am doing this for research pirposes. The Q factor at resonance is well known. I am interested to find out how the Q factor can be calculated from SPICE AC analysuis output at non resonance frequency bands.
Reply by ●October 30, 20212021-10-30
On Saturday, October 30, 2021 at 10:40:12 PM UTC+11, daku...@gmail.com wrote:> On Saturday, October 30, 2021 at 4:13:33 PM UTC+5:30, bill....@ieee.org wrote: > > On Saturday, October 30, 2021 at 5:34:59 PM UTC+11, daku...@gmail.com wrote: > > > Could some electronics guru here please clarify this ? S{OCE AC analysis allows measurement of small signal s parameters. Using these measured values, the elements of the impedance matrix(Z matrix - Z11, Z12, Z21 and Z22) cam be calculated(messy but straightforward calculation, done easily with C code) Once the elements of the Z matrix have been calculated, the input, output impedances of the 2 port network can be calculated(as before messy but straightforward calculation, easily done with C code). > > > For an inductor operating at RF|microwave frequencies in the non-resonant frequency range, the quality factor is > > > (wL/R(f)) w -> angular frequency, L inductance(geometry based) and R(f) > > > the frequency dependent resistance. So, if one were to measure the Q factor of a microstrip rectangular inductor e.g., at 759 MHz, which of Z11, Z12, Z21 , Z22 Zin, Zout would be used to get the Q factor? > > > All hints|suggestions will be greatly appreciated. Thanks in advance. > > The catch here is that the microstrip is a distributed inductance. > > > > The quality factor is for a lumped inductance. You might make more progress if you treated your microstrip as a series of transmission line elements. > > > > As is usual here, I'm going to point out that you might make more progress - and might even get some useful help - if you told us why you were making the measurement and what you wanted to do with the quality factor once you had extracted it. > > > > Most of this kind of stuff turns out to be somebody looking at a problem from the wrong point of view, and if the original poster backs up far enough somebody will recognise the problem and spell out the well-known approach that actually works. > > I am doing this for research purposes. The Q factor at resonance is well known. I am interested to find out how the Q factor can be calculated from SPICE AC analysis output at non resonance frequency bands.But what are you going to use it for? Q-factors in filter design are interesting to the extent that high Q-factors make transfer function for phase and amplitude change more rapidly with frequency around the cut-off frequency. This isn't going to work the same way with a distributed inductance. -- Bill Sloman, Sydney
Reply by ●October 30, 20212021-10-30
amal banerjee wrote:> Could some electronics guru here please clarify this ? S{OCE AC > analysis allows measurement of small signal s parameters. Using these > measured values, the elements of the impedance matrix(Z matrix - Z11, > Z12, Z21 and Z22) cam be calculated(messy but straightforward > calculation, done easily with C code) Once the elements of the Z > matrix have been calculated, the input, output impedances of the 2 > port network can be calculated(as before messy but straightforward > calculation, easily done with C code). For an inductor operating at > RF|microwave frequencies in the non-resonace frequency range, the > quality factor is (wL/R(f)) w -> angular frequency, L > inductance(geometry based) and R(f) the frequency dependent > resistance. So, if one were to measure the Q factor of a microstrip > rectangular inductor e.g., at 759 MHz, which of Z11, Z12, Z21 , Z22 > Zin, Zout would be used to get the Q factor? All hints|suggestions > will be greatly appreciated. Thanks in advance. >There are several definitions of Q, which are all pretty much equivalent in the high-Q limit but differ widely when Q <= 2-ish. omega_0 L/R ~ 1/(omega_0 R C) ~ 1/(logarithmic decrement per cycle), etc. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
Reply by ●October 31, 20212021-10-31
On Sunday, October 31, 2021 at 4:40:56 AM UTC+5:30, Phil Hobbs wrote:> amal banerjee wrote: > > Could some electronics guru here please clarify this ? S{OCE AC > > analysis allows measurement of small signal s parameters. Using these > > measured values, the elements of the impedance matrix(Z matrix - Z11, > > Z12, Z21 and Z22) cam be calculated(messy but straightforward > > calculation, done easily with C code) Once the elements of the Z > > matrix have been calculated, the input, output impedances of the 2 > > port network can be calculated(as before messy but straightforward > > calculation, easily done with C code). For an inductor operating at > > RF|microwave frequencies in the non-resonace frequency range, the > > quality factor is (wL/R(f)) w -> angular frequency, L > > inductance(geometry based) and R(f) the frequency dependent > > resistance. So, if one were to measure the Q factor of a microstrip > > rectangular inductor e.g., at 759 MHz, which of Z11, Z12, Z21 , Z22 > > Zin, Zout would be used to get the Q factor? All hints|suggestions > > will be greatly appreciated. Thanks in advance. > > > There are several definitions of Q, which are all pretty much equivalent > in the high-Q limit but differ widely when Q <= 2-ish. > > omega_0 L/R ~ 1/(omega_0 R C) ~ 1/(logarithmic decrement per cycle), etc. > > Cheers > > Phil Hobbs > -- > Dr Philip C D Hobbs > Principal Consultant > ElectroOptical Innovations LLC / Hobbs ElectroOptics > Optics, Electro-optics, Photonics, Analog Electronics > Briarcliff Manor NY 10510 > > http://electrooptical.net > http://hobbs-eo.comActually, the definition of the Q factor Q = wL/R(f) keads to an straightforward solution, given that impefance Z = R + j wL and L is geometry dependent. So the test setup in SPICE consists of a signal source connected in series to the test inductor and other end of the inductor is grounded. Then, for each each frequency (in the range to be considered) measure the voltage across the test onductor, and the current through it. Then |Z| = V/I. Using Z = R + j wL, and the measured value of |Z| at the test frequency, and calculated R(f), get wL and then Q.
Reply by ●October 31, 20212021-10-31
"the concepts "male" and "female" are essentially social constructions" (Bill Sloman) "the Mueller investigation was about Trump only because Trump made it so" (paraphrased) Bozo the Clown... -- Anthony William Sloman <bill.sloman@ieee.org> wrote:> X-Received: by 2002:a05:620a:1a84:: with SMTP id bl4mr4957876qkb.411.1635600275679; Sat, 30 Oct 2021 06:24:35 -0700 (PDT) > X-Received: by 2002:a25:37cb:: with SMTP id e194mr6161929yba.449.1635600275367; Sat, 30 Oct 2021 06:24:35 -0700 (PDT) > Path: eternal-september.org!reader02.eternal-september.org!news.uzoreto.com!tr3.eu1.usenetexpress.com!feeder.usenetexpress.com!tr2.iad1.usenetexpress.com!border1.nntp.dca1.giganews.com!nntp.giganews.com!news-out.google.com!nntp.google.com!postnews.google.com!google-groups.googlegroups.com!not-for-mail > Newsgroups: sci.electronics.design > Date: Sat, 30 Oct 2021 06:24:35 -0700 (PDT) > In-Reply-To: <d5fd27f5-bb94-44a4-a40a-ddf582f65f21n@googlegroups.com> > Injection-Info: google-groups.googlegroups.com; posting-host=203.213.69.109; posting-account=SJ46pgoAAABuUDuHc5uDiXN30ATE-zi- > NNTP-Posting-Host: 203.213.69.109 > References: <3933f0b1-24c6-42b8-a172-7d2ac67dc9c8n@googlegroups.com> <e223572b-5fbc-4198-aff0-f85a1afc02aan@googlegroups.com> <d5fd27f5-bb94-44a4-a40a-ddf582f65f21n@googlegroups.com> > User-Agent: G2/1.0 > MIME-Version: 1.0 > Message-ID: <f4591767-84cd-480a-9d19-ed4b43d90051n@googlegroups.com> > Subject: Re: Inductor Q factor calculation from SPICE AC analysis > From: Anthony William Sloman <bill.sloman@ieee.org> > Injection-Date: Sat, 30 Oct 2021 13:24:35 +0000 > Content-Type: text/plain; charset="UTF-8" > Content-Transfer-Encoding: quoted-printable > Lines: 48 > Xref: reader02.eternal-september.org sci.electronics.design:651013 > > On Saturday, October 30, 2021 at 10:40:12 PM UTC+11, daku...@gmail.com wrote: >> On Saturday, October 30, 2021 at 4:13:33 PM UTC+5:30, bill....@ieee.org w > rote: >> > On Saturday, October 30, 2021 at 5:34:59 PM UTC+11, daku...@gmail.com w > rote: >> > > Could some electronics guru here please clarify this ? S{OCE AC analy > sis allows measurement of small signal s parameters. Using these measured values, the elements of the impedance matrix(Z matrix - Z11, Z12, Z21 and Z22) cam be calculated(messy but straightforward calculation, done easily with C code) Once the elements of the Z matrix have been calculated, the input, output impedances of the 2 port network can be calculated(as before messy but straightforward calculation, easily done with C code). >> > > For an inductor operating at RF|microwave frequencies in the non-reso > nant frequency range, the quality factor is >> > > (wL/R(f)) w -> angular frequency, L inductance(geometry based) and R( > f) >> > > the frequency dependent resistance. So, if one were to measure the Q > factor of a microstrip rectangular inductor e.g., at 759 MHz, which of Z11, Z12, Z21 , Z22 Zin, Zout would be used to get the Q factor? >> > > All hints|suggestions will be greatly appreciated. Thanks in advance. > >> > The catch here is that the microstrip is a distributed inductance. >> > >> > The quality factor is for a lumped inductance. You might make more prog > ress if you treated your microstrip as a series of transmission line elements. >> > >> > As is usual here, I'm going to point out that you might make more progr > ess - and might even get some useful help - if you told us why you were making the measurement and what you wanted to do with the quality factor once you had extracted it. >> > >> > Most of this kind of stuff turns out to be somebody looking at a proble > m from the wrong point of view, and if the original poster backs up far enough somebody will recognise the problem and spell out the well-known approach that actually works. >> >> I am doing this for research purposes. The Q factor at resonance is well > known. I am interested to find out how the Q factor can be calculated from SPICE AC analysis output at non resonance frequency bands. > > But what are you going to use it for? Q-factors in filter design are interesting to the extent that high Q-factors make transfer function for phase and amplitude change more rapidly with frequency around the cut-off frequency. This isn't going to work the same way with a distributed inductance. > > -- > Bill Sloman, Sydney >
Reply by ●October 31, 20212021-10-31
On Sunday, October 31, 2021 at 5:50:24 PM UTC+11, John Doe wrote:> Anthony William Sloman <bill....@ieee.org> wrote: > > On Saturday, October 30, 2021 at 10:40:12 PM UTC+11, daku...@gmail.com wrote: > >> On Saturday, October 30, 2021 at 4:13:33 PM UTC+5:30, bill....@ieee.org w > > rote: > >> > On Saturday, October 30, 2021 at 5:34:59 PM UTC+11, daku...@gmail.com w > > rote: > >> > > Could some electronics guru here please clarify this ? S{OCE AC analy > > sis allows measurement of small signal s parameters. Using these measured values, the elements of the impedance matrix(Z matrix - Z11, Z12, Z21 and Z22) cam be calculated(messy but straightforward calculation, done easily with C code) Once the elements of the Z matrix have been calculated, the input, output impedances of the 2 port network can be calculated(as before messy but straightforward calculation, easily done with C code). > >> > > For an inductor operating at RF|microwave frequencies in the non-reso > > nant frequency range, the quality factor is > >> > > (wL/R(f)) w -> angular frequency, L inductance(geometry based) and R( > > f) > >> > > the frequency dependent resistance. So, if one were to measure the Q > > factor of a microstrip rectangular inductor e.g., at 759 MHz, which of Z11, Z12, Z21 , Z22 Zin, Zout would be used to get the Q factor? > >> > > All hints|suggestions will be greatly appreciated. Thanks in advance. > > > >> > The catch here is that the microstrip is a distributed inductance. > >> > > >> > The quality factor is for a lumped inductance. You might make more prog > > ress if you treated your microstrip as a series of transmission line elements. > >> > > >> > As is usual here, I'm going to point out that you might make more progr > > ess - and might even get some useful help - if you told us why you were making the measurement and what you wanted to do with the quality factor once you had extracted it. > >> > > >> > Most of this kind of stuff turns out to be somebody looking at a proble > > m from the wrong point of view, and if the original poster backs up far enough somebody will recognise the problem and spell out the well-known approach that actually works. > >> > >> I am doing this for research purposes. The Q factor at resonance is well > > known. I am interested to find out how the Q factor can be calculated from SPICE AC analysis output at non resonance frequency bands. > > > > But what are you going to use it for? Q-factors in filter design are interesting to the extent that high Q-factors make transfer function for phase and amplitude change more rapidly with frequency around the cut-off frequency. This isn't going to work the same way with a distributed inductance.John Doe hasn't got a clue what any of this is about, but feels the need to stick his oar in anyway. I've snipped his irrelevant comments. About all that they showed was that he didn't have anything useful to say, which does seem to be generally true. -- Bill Sloman, Sydney
Reply by ●October 31, 20212021-10-31
"the concepts "male" and "female" are essentially social constructions" (Bill Sloman) "the Mueller investigation was about Trump only because Trump made it so" (paraphrased) Bozo the Clown... -- Anthony William Sloman <bill.sloman@ieee.org> wrote:> X-Received: by 2002:ac8:7e96:: with SMTP id w22mr22245165qtj.28.1635665416293; Sun, 31 Oct 2021 00:30:16 -0700 (PDT) > X-Received: by 2002:a25:b294:: with SMTP id k20mr20276009ybj.232.1635665415997; Sun, 31 Oct 2021 00:30:15 -0700 (PDT) > Path: eternal-september.org!reader02.eternal-september.org!weretis.net!feeder8.news.weretis.net!proxad.net!feeder1-2.proxad.net!209.85.160.216.MISMATCH!news-out.google.com!nntp.google.com!postnews.google.com!google-groups.googlegroups.com!not-for-mail > Newsgroups: sci.electronics.design > Date: Sun, 31 Oct 2021 00:30:15 -0700 (PDT) > In-Reply-To: <slleb8$t69$12@dont-email.me> > Injection-Info: google-groups.googlegroups.com; posting-host=203.213.69.109; posting-account=SJ46pgoAAABuUDuHc5uDiXN30ATE-zi- > NNTP-Posting-Host: 203.213.69.109 > References: <3933f0b1-24c6-42b8-a172-7d2ac67dc9c8n@googlegroups.com> <e223572b-5fbc-4198-aff0-f85a1afc02aan@googlegroups.com> <d5fd27f5-bb94-44a4-a40a-ddf582f65f21n@googlegroups.com> <f4591767-84cd-480a-9d19-ed4b43d90051n@googlegroups.com> <slleb8$t69$12@dont-email.me> > User-Agent: G2/1.0 > MIME-Version: 1.0 > Message-ID: <42189cf7-691f-4fc3-a9e4-167b02d2454cn@googlegroups.com> > Subject: Re: Inductor Q factor calculation from SPICE AC analysis > From: Anthony William Sloman <bill.sloman@ieee.org> > Injection-Date: Sun, 31 Oct 2021 07:30:16 +0000 > Content-Type: text/plain; charset="UTF-8" > Content-Transfer-Encoding: quoted-printable > Xref: reader02.eternal-september.org sci.electronics.design:651092 > > On Sunday, October 31, 2021 at 5:50:24 PM UTC+11, John Doe wrote: >> Anthony William Sloman <bill....@ieee.org> wrote: >> > On Saturday, October 30, 2021 at 10:40:12 PM UTC+11, daku...@gmail.com > wrote: >> >> On Saturday, October 30, 2021 at 4:13:33 PM UTC+5:30, bill....@ieee.or > g w >> > rote: >> >> > On Saturday, October 30, 2021 at 5:34:59 PM UTC+11, daku...@gmail.co > m w >> > rote: >> >> > > Could some electronics guru here please clarify this ? S{OCE AC an > aly >> > sis allows measurement of small signal s parameters. Using these measur > ed values, the elements of the impedance matrix(Z matrix - Z11, Z12, Z21 and Z22) cam be calculated(messy but straightforward calculation, done easily with C code) Once the elements of the Z matrix have been calculated, the input, output impedances of the 2 port network can be calculated(as before messy but straightforward calculation, easily done with C code). >> >> > > For an inductor operating at RF|microwave frequencies in the non-r > eso >> > nant frequency range, the quality factor is >> >> > > (wL/R(f)) w -> angular frequency, L inductance(geometry based) and > R( >> > f) >> >> > > the frequency dependent resistance. So, if one were to measure the > Q >> > factor of a microstrip rectangular inductor e.g., at 759 MHz, which of > Z11, Z12, Z21 , Z22 Zin, Zout would be used to get the Q factor? >> >> > > All hints|suggestions will be greatly appreciated. Thanks in advan > ce. >> > >> >> > The catch here is that the microstrip is a distributed inductance. > >> >> > >> >> > The quality factor is for a lumped inductance. You might make more p > rog >> > ress if you treated your microstrip as a series of transmission line el > ements. >> >> > >> >> > As is usual here, I'm going to point out that you might make more pr > ogr >> > ess - and might even get some useful help - if you told us why you were > making the measurement and what you wanted to do with the quality factor once you had extracted it. >> >> > >> >> > Most of this kind of stuff turns out to be somebody looking at a pro > ble >> > m from the wrong point of view, and if the original poster backs up far > enough somebody will recognise the problem and spell out the well-known approach that actually works. >> >> >> >> I am doing this for research purposes. The Q factor at resonance is we > ll >> > known. I am interested to find out how the Q factor can be calculated f > rom SPICE AC analysis output at non resonance frequency bands. >> > >> > But what are you going to use it for? Q-factors in filter design are in > teresting to the extent that high Q-factors make transfer function for phase and amplitude change more rapidly with frequency around the cut-off frequency. This isn't going to work the same way with a distributed inductance. > > John Doe hasn't got a clue what any of this is about, but feels the need to stick his oar in anyway. I've snipped his irrelevant comments. > > About all that they showed was that he didn't have anything useful to say, which does seem to be generally true. > > -- > Bill Sloman, Sydney > > >
Reply by ●October 31, 20212021-10-31
The John Doe troll stated the following in message-id <sdhn7c$pkp$4@dont-email.me>:> The troll doesn't even know how to format a USENET post...And the John Doe troll stated the following in message-id <sg3kr7$qt5$1@dont-email.me>:> The reason Bozo cannot figure out how to get Google to keep from > breaking its lines in inappropriate places is because Bozo is > CLUELESS...And yet, the clueless John Doe troll has itself posted yet another incorrectly formatted USENET posting on Sun, 31 Oct 2021 06:50:17 -0000 (UTC) in message-id <slleb8$t69$12@dont-email.me>. snoPwc8bD+I4
