How to determine Zin, Yout for RF transistor, from A parameters

>"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. :-)

-- Kevin Aylward
http://www.anasoft.co.uk - SuperSpice
http://www.kevinaylward.co.uk/ee/index.html 

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

On a sunny day (Sat, 6 May 2017 23:39:14 +0100) it happened "Kevin Aylward"
<kevinRemovAT@kevinaylward.co.uk> wrote in

>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?



>I await Jim Ts response :-)

That is predicatable, he designs sjips.
With all respect to JT.


Did you try string theory?

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?

On Sat, 06 May 2017 19:26:59 -0400, bitrex 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.
> 
> So go die in a fire, pal.

What do you expect when you post such a lame platitude, Captain Obvious?

On Sat, 06 May 2017 16:09:02 -0700, John Larkin wrote:

> How do you know what to simulate? Just plunking parts on a screen and
> running Spice only works for very simple circuits. 

You will have just incurred Kev's wrath with this remark, John. Expect to 
be beaten into a pulp by attrition.

On Sun, 07 May 2017 08:55:17 +0100, Kevin Aylward wrote:
 
> 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. :-)

FMOB! Perish the thought, Kev. ;->

On Sat, 06 May 2017 19:14:45 -0500, Tim Williams wrote:

> Measured:
> https://www.seventransistorlabs.com/ClassD1/Images/
ClassD_GateWavScope.jpg


FFS, Tim. Your scope's screen is so scratched it's hard to tell the 
traces from the scars!

On Sun, 7 May 2017 10:47:22 -0000 (UTC), Cursitor Doom
<curd@notformail.com> wrote:

>On Sat, 06 May 2017 16:09:02 -0700, John Larkin wrote:
>
>> How do you know what to simulate? Just plunking parts on a screen and
>> running Spice only works for very simple circuits. 
>
>You will have just incurred Kev's wrath with this remark, John. Expect to 
>be beaten into a pulp by attrition.

Maybe SuperSpice accepts a short verbal description of what you want,
and how much it should cost.


-- 

John Larkin         Highland Technology, Inc

lunatic fringe electronics 

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.

>
>So go die in a fire, pal.

You first you village idiot.
		
                                        ...Jim Thompson
-- 
| James E.Thompson                                 |    mens     |
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