On Sun, 7 May 2017 08:55:17 +0100, "Kevin Aylward" <kevinRemovAT@kevinaylward.co.uk> wrote:>>"Jim Thompson" wrote in message >>news:sflsgct5id9oji7ktkc1rj0i4d2q5hlrb8@4ax.com... > >> >>>Smith charts are super fast and intuitive, as well. >> >>Yeah... >> >>>A single analytical result is worth more than a stack of simulations. >> >>Hardly ever, today. You are obviously not someone that needs to design >>ASICs, that work first time, and work in their millions. > >>I experienced this year a bad case of a "team" of analog "designers" >>whose only "skill set" is cutting and pasting from their textbooks :-( > >One of the basic problems with text books, is that they are typically >written by those that went from the chain of school, to uni to learn, then >stay at uni to teach. They pretty much invariably have no idea how real, >commercial design is done. > >Another problem, is IEEE papers. People piss about with some supposed >theory, show some results that appear to match, and claim wonderful things >for their theory. Pretty much all of them on phase noise, are wrong. The >results are either in error, coincidental, delusionary or lies. Yes, some >have to be lies as there is no other rational explanation when the theory is >so far out to lunch. > >Just one example is here from Behzad Razavi (who writes text books): > >www.seas.ucla.edu/brweb/papers/Journals/BRMar96.pdf - "A Study of Phase >Noise in CMOS Oscillators," > >Pretty much everyone treats an oscillator as if it is an amplifier with a >signal at the oscillator amplitude and frequency added to a noise signal. >This is fundamentally flawed. An oscillator is an automatous signal >generator. As soon as the noise moves the phase/frequency, of the oscillator >output, the mix products change from what they would have been if the signal >was an independent one, because the oscillator, dah...has changed frequency. >This results in the inability to add up all noise generators by calculating >the effect of each one separately. Second, they all attempt an analysis by >using the power series describing the amplitude nonlinearity. This is >fundamentally flawed as well. The oscillator frequency is set by is loop >phase being zero. When the noise changes the value of the nonlinear >capacitances in the circuit, the loop phase changes, hence there is direct >FM modulation. One therefore needs to calculate the phase response with >amplitude, not amplitude distortion. The reality is that, it is impossible >to design high performance oscillators that beat the competition without >using simulation tools (PSSN). Manual calculations are just too difficult. > >Indeed, the above Razavi paper includes "multiplicative" noise of Osc >frequency X noise frequency due to nonlinear amplitude mixing. However, >Sin(w_o.t).Sin(w_n.t) is amplitude noise not phase noise. The zero xings of >the the product due to the osc don't change. "multiplicative" noise has only >an indirect effect on final phase noise. Simply clueless, yet these are the >guys teaching the newbies. > >The crunch is all here: > >http://www.kevinaylward.co.uk/ee/phasenoise/phasenoise.html > >So Jim, baring in mind that I have now been around 9 years at www.rakon.com, >and extensively investigated 100s of oscillator topologies and 100,000s of >osc simulations, it would, pretty much, make me a world leading authority on >high performance oscillators, not that I am ever one of those types that >brag on NGs. :-)A couple of people (TAITIEN, ABRACON) are making 1" square OCXOs with astounding phase noise specs, for around $80. I wonder if they are SC cuts. Does Rakon have anything like that? We are building a test rig that will slowly walk two edges across each other, D and clk into a super-fast SiGe flipflop. One flop input will be a super-good OCXO. We'll look at the averaged Q output to compute time jitter. So we can measure the jitter of longish time delays cheap. https://dl.dropboxusercontent.com/u/53724080/Circuits/Fast_Stuff/NB7_Steps.jpg Looks like we'll be in the 60 fs RMS sort of range on edge detection, so the OCXO jitter will dominate. -- John Larkin Highland Technology, Inc lunatic fringe electronics
How to determine Zin, Yout for RF transistor, from A parameters
Started by ●May 6, 2017
Reply by ●May 7, 20172017-05-07
Reply by ●May 7, 20172017-05-07
On Sun, 07 May 2017 09:07:16 GMT, Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> wrote:>On a sunny day (Sun, 7 May 2017 09:21:23 +0100) it happened "Kevin Aylward" ><kevinRemovAT@kevinaylward.co.uk> wrote in ><zaKdnRkW38ieRJPEnZ2dnUU7-TPNnZ2d@giganews.com>: > >>wrote in message >>news:e9130191-9658-42f9-bade-df2eb7861db6@googlegroups.com... >> >>>S parameter design for transistor circuits is, essentially, a legacy >>>claptrap rut, that many just can't get out off. >> >>>You're obviously not an RF guy. S parameters let you calculate >>>analytically things like the stability boundary, active vs passive regions, >>>maximum available gain, and so on. >> >>>Smith charts are super fast and intuitive, as well. >> >>>There are cases that are too hard analytically, but one-transistor >>>microwave amps are not among them. >> >>Denied. >> >>In fact, I will give you a challenge. I will pay you $1,000, and you will >>pay me $100 if you can beat me on a design for a 100MHz (ease of testing) >>oscillator. The basic conditions being. >> >>1 No experimental work. The oscillator must work correctly first time build. >> >>2 You design based solely on S parameters of the transistors, data sheet and >>paper calculations, with no DC, or TRAN simulations, because you don't have >>the spice model. >> >>3 I design based solely on the spice model using Cadence, including PSS and >>PSS Noise, TRAN and DC. >> >>4 A noise performance and current spec will be agreed. You win if I don't >>produce a design that is at least 1/4 your design's current and 10dB lower >>phase noise. >> >>It would be like liking sweets from a baby. Trust me. >> >>http://www.kevinaylward.co.uk/ee/phasenoise/phasenoise.html >> >>The reality is, most "RF guys", can't design a minskirt. I have interviewed >>many. Their minds are filled with nebulous frequency domain claptrap, they >>don't actually understand that transistor level design is about volts, amps >>and time. Other than a simply resister bias, they are usually clueless. >> >>-- Kevin Aylward >>http://www.anasoft.co.uk - SuperSpice >>http://www.kevinaylward.co.uk/ee/index.html >> > >You do not need S params, nor Spice to design a `100 MHz osc'. >And I hope you mean BUILD a physical working, >your slimulation doing better is just that, string theroy. > > yer good old JFET > |-------------- choke--- + 12 > ------------>| | > | | |-- | > | === C | | > L |------------| === > | === [ ] | decoupling > | | 2C | 1k | > ---------------------------------- GND > > >Worked for me. > >You never actually build any RF did you?I was toying with the idea of building an XO with extremely low harmonic distortion. It would be a colpitts, like your circuit, but with weak feedback coupling, and a separate low-distortion buffer directly off the crystal. What I'll probably do is just use one of our DDS-based arbs to make a pretty good sine wave, and lowpass filter the heck out of that. -- John Larkin Highland Technology, Inc lunatic fringe electronics
Reply by ●May 7, 20172017-05-07
On Sun, 07 May 2017 08:25:53 -0700, Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:>On Sat, 6 May 2017 19:26:59 -0400, bitrex ><bitrex@de.lete.earthlink.net> wrote: > >>On 05/06/2017 05:18 PM, Cursitor Doom wrote: >>> On Sat, 06 May 2017 14:12:38 -0400, bitrex wrote: >>> >>>> If you know how to use a Smith chart you can design an impedance >>>> matching network for same amp in about 5 minutes that would take you the >>>> better part of an hour to grunge thru on paper >>> >>> Well no shit, Sherlock. >>> >> >>The grandparent poster may not have. > >That's a remarkably ignorant statement. During my youth slide rules >and Smith Charts were taught in high school and college.At least in my youth, linear and circulative slide rules were used in something comparable to high school. Smith Charts were thought in a technical university not in high school.
Reply by ●May 7, 20172017-05-07
On 05/07/2017 11:25 AM, Jim Thompson wrote:> On Sat, 6 May 2017 19:26:59 -0400, bitrex > <bitrex@de.lete.earthlink.net> wrote: > >> On 05/06/2017 05:18 PM, Cursitor Doom wrote: >>> On Sat, 06 May 2017 14:12:38 -0400, bitrex wrote: >>> >>>> If you know how to use a Smith chart you can design an impedance >>>> matching network for same amp in about 5 minutes that would take you the >>>> better part of an hour to grunge thru on paper >>> >>> Well no shit, Sherlock. >>> >> >> The grandparent poster may not have. > > That's a remarkably ignorant statement. During my youth slide rules > and Smith Charts were taught in high school and college. > > For the first 15 years out of school there were no Spice simulators.Tell us more about how things were prior to the Great Flood!
Reply by ●May 7, 20172017-05-07
"Jan Panteltje" wrote in message news:oekvo1$jak$1@news.datemas.de... On a sunny day (Sat, 6 May 2017 11:24:14 -0500) it happened "Tim Williams" <tiwill@seventransistorlabs.com> wrote in <oekt4r$aoj$1@dont-email.me>:>Sadly, a ton of transistors just don't give that info. > >Some don't even give s-params, or their LF equivalents (junction C's, >internal resistances, etc.). > >The OP wasn't exactly specific... > >It's nice to just keep shopping for a part that does, but if this is going >deep into the rarefied territory of RF (the OP wasn't exactly specific >:) ), >you can be SOL very easily. > >Tim > >-- >Seven Transistor Labs, LLC >Electrical Engineering Consultation and Contract Design >Website: http://seventransistorlabs.com > > >"Kevin Aylward" <kevinRemovAT@kevinaylward.co.uk> wrote in message >news:pKqdnS_JAfH24JDEnZ2dnUU7-L3NnZ2d@giganews.com... >> wrote in message >> news:394a6d1b-52b4-4864-845a-517591c881b3@googlegroups.com... >> >>>Could some RGF/microwave guru on this newsgroup >>>please help ? I am looking at the datasheet for >>>a ONSemi RF transistor, with the S parameters >>>listed for various frequencies. What would be >>>a quick and easy(that I can code as a simple >>>C program) way to convert these to the >>>corresponding Zin and Yout. Thanks in >>>advance for your hints/suggestions. >> >> Why? >> >> Try and find the spice model, and do everything in spice. >> >> One of the remain reasons for stuff like S parameters, was simply that it >> was easier to measure than other ones in the distant past. Its simply all >> irrelevant now. We have simulation tools. >> >> S parameters are way too limiting for optimum design. Usually, they are >> only specified for one or a few current/voltage sets, and they are only >> useful at all for linear analysis. This is a disaster for decent optimum >> production design.s >> >> S parameter design for transistor circuits is, essentially, a legacy >> claptrap rut, that many just can't get out off. >> >> A good spice model will allow you do accurately design over the whole >> range of operating currents and voltages including the required >> transient, >> real world large signals that the circuit is actually being used for. >>>These days people run simulations, and really they remind me of NASA, >in the sense that when NASA detects a new planet,....>...AND on top of that, if you have your spice working, you have NOTHING, >it is all illusion like that movie, and ...Unfortunately, you have absolutely no idea whatsoever about modern electronic asic design, and I mean that you are completely clueless on that matter. Your implication that one has to piss about on a breadboard after designing in the simulation universe, is wrong. Period. Its simply fact that 100,000s of ascis with up to billions of transistors are designed entirely in simulation, and a very large % of them work correctly, first time. I have given a lecture on this several time before in this NG. Look it up. Some processes cost 1/2 million dollars for a set of masks. Do you really think that a company is going throw that money down the toilet? Analog ones are more challenging, but essentially, the chief reason, imo, why an analog asic don't work first pass, is because the designer wasn't the full shilling, not that there is any issue with designing in the virtual world. -- Kevin Aylward http://www.anasoft.co.uk - SuperSpice http://www.kevinaylward.co.uk/ee/index.html
Reply by ●May 7, 20172017-05-07
"Jan Panteltje" wrote in message news:oemo45$n42$1@news.datemas.de... On a sunny day (Sun, 7 May 2017 09:21:23 +0100) it happened "Kevin Aylward" <kevinRemovAT@kevinaylward.co.uk> wrote in <zaKdnRkW38ieRJPEnZ2dnUU7-TPNnZ2d@giganews.com>:>wrote in message >news:e9130191-9658-42f9-bade-df2eb7861db6@googlegroups.com... > >>S parameter design for transistor circuits is, essentially, a legacy >>claptrap rut, that many just can't get out off. > >>You're obviously not an RF guy. S parameters let you calculate >>analytically things like the stability boundary, active vs passive >>regions, >>maximum available gain, and so on. > >>Smith charts are super fast and intuitive, as well. > >>There are cases that are too hard analytically, but one-transistor >>microwave amps are not among them. > >Denied. > >In fact, I will give you a challenge. I will pay you $1,000, and you will >pay me $100 if you can beat me on a design for a 100MHz (ease of testing) >oscillator. The basic conditions being. > >1 No experimental work. The oscillator must work correctly first time >build. > >2 You design based solely on S parameters of the transistors, data sheet >and >paper calculations, with no DC, or TRAN simulations, because you don't have >the spice model. > >3 I design based solely on the spice model using Cadence, including PSS and >PSS Noise, TRAN and DC. > >4 A noise performance and current spec will be agreed. You win if I don't >produce a design that is at least 1/4 your design's current and 10dB lower >phase noise. > >It would be like liking sweets from a baby. Trust me. > >http://www.kevinaylward.co.uk/ee/phasenoise/phasenoise.html > >The reality is, most "RF guys", can't design a minskirt. I have interviewed >many. Their minds are filled with nebulous frequency domain claptrap, they >don't actually understand that transistor level design is about volts, amps >and time. Other than a simply resister bias, they are usually clueless. > >-- Kevin Aylward >http://www.anasoft.co.uk - SuperSpice >http://www.kevinaylward.co.uk/ee/index.html >>You do not need S params, nor Spice to design a `100 MHz osc'. >And I hope you mean BUILD a physical working, >your slimulation doing better is just that, string theroy.You are clearly completely clueless on modern, high performance oscillator design. Fortunately for those that buy iPhones, TX and RX design is, essentially, all done in the virtual world, otherwise making 50 million a quarter reliably would be truly impossible. Sure, there is may be a bit of manual tweaking but you wont get a contract from Apple without having an army of verification engineers producing documentation on the simulations on the chips you're flogging to them. I actually have a mate who does just that. yer good old JFET |-------------- choke--- + 12 ------------>| | | | |-- | | === C | | L |------------| === | === [ ] | decoupling | | 2C | 1k | ---------------------------------- GND Ho hummm... That is not an oscillator. It, may be in another universe, a part of $5 dick tracy walky talki for children.>Worked for me.What is its phase noise? What is is stability over temperature and power supply variations? How many will be in spec out of a million made? What is its spec? What's its frequency sensitivity to load? ....>You never actually build any RF did you?I don't build anything today, I haven't for many years. I modied my Marshall amp a while back though. It had a || loop for the effects. Ho humm... However, I do have an OCXO asic in production that runs up to 100MHz, has a few ppb stability, and flat band phase noise approaching -165db, in a very small package. How about you? -- Kevin Aylward http://www.anasoft.co.uk - SuperSpice http://www.kevinaylward.co.uk/ee/index.html
Reply by ●May 7, 20172017-05-07
"Jan Panteltje" wrote in message news:oemmll$kh5$1@news.datemas.de... On a sunny day (Sat, 6 May 2017 23:39:14 +0100) it happened "Kevin Aylward" <kevinRemovAT@kevinaylward.co.uk> wrote in -----Original Message----- From: hgw@.... Sent: Sunday, May 07, 2017 1:48 AM Newsgroups: sci.physics.relativity Subject: Re: non-coordinate basis On 07/05/17 02:43, Kevin Aylward wrote:> "HGW... DSc." wrote in message news:oec62r$knk$1@gioia.aioe.org...>>> >>> Of course there is. I have actually done a physics lab on measuring the >>> e/m ratio on a CRT by deflection of the beam myself. Its needs the mass >>> increase formula. >> >>> It isn't a mass increase. Even relativists have dropped that idea > >> So, why did you think I wrote "requires the mass increase formula".>The 'mass increase' is not really a mass increase.I wrote this over 15 yeas ago: http://www.kevinaylward.co.uk/gr/emc2/emc2.html again, now pay attention to the statement just before the summary.>>Kevin Aylward >>http://www.kevinaylward.co.uk/gr/index.html >>http://www.kevinaylward.co.uk/qm/index.html >>Nonsense. Accurate one transistor circuits are not solvable, especially >>for >>worst case conditions. Period. > >>An illustration of this is the effort involved in simply solving for the >>currents in an ideal transistor with just an emitter resister. > >>http://www.kevinaylward.co.uk/ee/widlarlambert/widlarlambert.xht > >>Now add in capacitances early effect, rb, rc and hfe variation with >>current. >>Its a complete non starter.>My response, a question, >show me a RF circuit you actually build lately? >Preferably GHz?Address my actual points first. Like, 1 What can NOT be done in spice that MUST be done using S parameters 2 Explain how one does phase noise, distortion, bias design and power optimisation using just S parameters. I want to know how *you* design high performance, competitive, oscillators using only S parameters. I have told you how I do it. -- Kevin Aylward http://www.anasoft.co.uk - SuperSpice http://www.kevinaylward.co.uk/ee/index.html
Reply by ●May 7, 20172017-05-07
"Jim Thompson" wrote in message news:toeugctj4jg00n4nh8j7olqupvadn7p78m@4ax.com... On Sat, 6 May 2017 19:26:59 -0400, bitrex <bitrex@de.lete.earthlink.net> wrote:>On 05/06/2017 05:18 PM, Cursitor Doom wrote: >> On Sat, 06 May 2017 14:12:38 -0400, bitrex wrote: >> >>> If you know how to use a Smith chart you can design an impedance >>> matching network for same amp in about 5 minutes that would take you the >>> better part of an hour to grunge thru on paper >> >> Well no shit, Sherlock. >> > >The grandparent poster may not have.>That's a remarkably ignorant statement. During my youth slide rules >and Smith Charts were taught in high school and college.Indeed, and we no longer use slide rules. Although, Jim, being that you are somewhat mature now, it may be that you can't avoid relapsing to your childhood...>For the first 15 years out of school there were no Spice simulators.Indeed, and we now do use Spice -- Kevin Aylward http://www.anasoft.co.uk - SuperSpice http://www.kevinaylward.co.uk/ee/index.html
Reply by ●May 7, 20172017-05-07
On 07/05/2017 20:52, Kevin Aylward wrote:> Analog ones are more challenging, but essentially, the chief reason,And oranges are much better than apples.
Reply by ●May 7, 20172017-05-07
On a sunny day (Sun, 7 May 2017 20:52:06 +0100) it happened "Kevin Aylward" <kevinRemovAT@kevinaylward.co.uk> wrote in <_8ydnc43f9p655LEnZ2dnUU7-WfNnZ2d@giganews.com>:>"Jan Panteltje" wrote in message news:oekvo1$jak$1@news.datemas.de... > >On a sunny day (Sat, 6 May 2017 11:24:14 -0500) it happened "Tim Williams" ><tiwill@seventransistorlabs.com> wrote in <oekt4r$aoj$1@dont-email.me>: > >>Sadly, a ton of transistors just don't give that info. >> >>Some don't even give s-params, or their LF equivalents (junction C's, >>internal resistances, etc.). >> >>The OP wasn't exactly specific... >> >>It's nice to just keep shopping for a part that does, but if this is going >>deep into the rarefied territory of RF (the OP wasn't exactly specific >>:) ), >>you can be SOL very easily. >> >>Tim >> >>-- >>Seven Transistor Labs, LLC >>Electrical Engineering Consultation and Contract Design >>Website: http://seventransistorlabs.com >> >> >>"Kevin Aylward" <kevinRemovAT@kevinaylward.co.uk> wrote in message >>news:pKqdnS_JAfH24JDEnZ2dnUU7-L3NnZ2d@giganews.com... >>> wrote in message >>> news:394a6d1b-52b4-4864-845a-517591c881b3@googlegroups.com... >>> >>>>Could some RGF/microwave guru on this newsgroup >>>>please help ? I am looking at the datasheet for >>>>a ONSemi RF transistor, with the S parameters >>>>listed for various frequencies. What would be >>>>a quick and easy(that I can code as a simple >>>>C program) way to convert these to the >>>>corresponding Zin and Yout. Thanks in >>>>advance for your hints/suggestions. >>> >>> Why? >>> >>> Try and find the spice model, and do everything in spice. >>> >>> One of the remain reasons for stuff like S parameters, was simply that it >>> was easier to measure than other ones in the distant past. Its simply all >>> irrelevant now. We have simulation tools. >>> >>> S parameters are way too limiting for optimum design. Usually, they are >>> only specified for one or a few current/voltage sets, and they are only >>> useful at all for linear analysis. This is a disaster for decent optimum >>> production design.s >>> >>> S parameter design for transistor circuits is, essentially, a legacy >>> claptrap rut, that many just can't get out off. >>> >>> A good spice model will allow you do accurately design over the whole >>> range of operating currents and voltages including the required >>> transient, >>> real world large signals that the circuit is actually being used for. >>> > > >>These days people run simulations, and really they remind me of NASA, >>in the sense that when NASA detects a new planet, >.... >>...AND on top of that, if you have your spice working, you have NOTHING, >>it is all illusion like that movie, and ... > >Unfortunately, you have absolutely no idea whatsoever about modern >electronic asic design, and I mean that you are completely clueless on that >matter. Your implication that one has to piss about on a breadboard after >designing in the simulation universe, is wrong. Period. > >Its simply fact that 100,000s of ascis with up to billions of transistors >are designed entirely in simulation, and a very large % of them work >correctly, first time. > >I have given a lecture on this several time before in this NG. Look it up. >Some processes cost 1/2 million dollars for a set of masks. Do you really >think that a company is going throw that money down the toilet? > >Analog ones are more challenging, but essentially, the chief reason, imo, >why an analog asic don't work first pass, is because the designer wasn't the >full shilling, not that there is any issue with designing in the virtual >world. > >-- Kevin Aylward >http://www.anasoft.co.uk - SuperSpice >http://www.kevinaylward.co.uk/ee/index.htmlHow ** impressive, and that is why you now need a Russian taxi to lower earth orbit. 2017 - 1969 = 48 years of moving backwards.
