On Sun, 15 Feb 2004 16:46:32 -0700, Jim Thompson
wrote:

On Sun, 15 Feb 2004 23:48:47 +0000, Paul Burridge
wrote:

What's the maximum multiplication factor it's practical and sensible
to attempt to achieve in one single stage of multiplication? (Say from
a 7Mhz square wave source with 5nS rise/fall times.)

You ought to be able to answer that yourself... what's the spectral
roll-off of a square wave ??

I suppose it boils down to how much signal is left in the mush as the
harmonics get higher and higher. Knew I shoulda held on to that
spectrum analyser I used to have. :-(
I suppose that's the proper answer though: get the rise/fall times as
small and possible, measure the specral output and pick a suitable
harmonic with enough energy in it to set it 'comfortably' above the
noise floor?
--

The BBC: Licensed at public expense to spread lies.

"Jim Thompson" wrote in message
...
On Mon, 16 Feb 2004 00:18:49 GMT, "W3JDR" wrote:

I would think a "W3JDR" would know that even harmonics are *much*
harder to obtain in nonlinear multipliers.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |


One would think a "PE" could give the man a civil answer.

Pete

"Jim Thompson" wrote in message
...
On Mon, 16 Feb 2004 00:18:49 GMT, "W3JDR" wrote:

I would think a "W3JDR" would know that even harmonics are *much*
harder to obtain in nonlinear multipliers.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |


One would think a "PE" could give the man a civil answer.

Pete

I would think a "W3JDR" would know that even harmonics are *much*
harder to obtain in nonlinear multipliers.

I guessed I missed Jim's comment in the earlier post, or I would have replied earlier.
Jim, I'm not not sure what you're trying to say, but there seems to be a sarcastic undertone to the way you said it.

Anyway, it turns out that non-linear single-ended elements are great generators of even-order harmonics. That's why the classical HF/VHF multiplier circuit is typically a single ended transistor amplifier with output and input tuned to different frequencies. If you bias the device so it is non-linear, then it becomes a natural harmonic generator. You can enhance even-order generation and supress the odd-order generation by using a non-linear 'push-push' stage, just as you can suppress even order harmonics with a 'push-pull' stage.

In either case, the important thing to remember is that symmetrical clipping or limiting generates mostly odd-order distortion and unsymmetrical clipping or limiting generates mostly even order distortion. The quantification of this is left to those more mathematically inclined.

Joe
W3JDR

I would think a "W3JDR" would know that even harmonics are *much*
harder to obtain in nonlinear multipliers.

I guessed I missed Jim's comment in the earlier post, or I would have replied earlier.
Jim, I'm not not sure what you're trying to say, but there seems to be a sarcastic undertone to the way you said it.

Anyway, it turns out that non-linear single-ended elements are great generators of even-order harmonics. That's why the classical HF/VHF multiplier circuit is typically a single ended transistor amplifier with output and input tuned to different frequencies. If you bias the device so it is non-linear, then it becomes a natural harmonic generator. You can enhance even-order generation and supress the odd-order generation by using a non-linear 'push-push' stage, just as you can suppress even order harmonics with a 'push-pull' stage.

In either case, the important thing to remember is that symmetrical clipping or limiting generates mostly odd-order distortion and unsymmetrical clipping or limiting generates mostly even order distortion. The quantification of this is left to those more mathematically inclined.

Joe
W3JDR

On Mon, 16 Feb 2004 17:02:20 GMT, "W3JDR" wrote:

I would think a "W3JDR" would know that even harmonics are *much*
harder to obtain in nonlinear multipliers.

I guessed I missed Jim's comment in the earlier post, or I would have replied earlier.
Jim, I'm not not sure what you're trying to say, but there seems to be a sarcastic undertone to the way you said it.

Only mildly so, just "funning" you ;-)


Anyway, it turns out that non-linear single-ended elements are great generators of even-order harmonics. That's why the classical HF/VHF multiplier circuit is typically a single ended transistor amplifier with output and input tuned to different frequencies. If you bias the device so it is non-linear, then it becomes a natural harmonic generator. You can enhance even-order generation and supress the odd-order generation by using a non-linear 'push-push' stage, just as you can suppress even order harmonics with a 'push-pull' stage.

In either case, the important thing to remember is that symmetrical clipping or limiting generates mostly odd-order distortion and unsymmetrical clipping or limiting generates mostly even order distortion. The quantification of this is left to those more mathematically inclined.

Joe
W3JDR

It depends on what your are starting from. If it's a sine wave, yes
even harmonics can be made from diode non-linearities.

The OP has a inverter-style XTAL oscillator, output very nearly
square.

A square wave is rich in odd harmonics, a perfect square wave has NO
even harmonics.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

On Mon, 16 Feb 2004 17:02:20 GMT, "W3JDR" wrote:

I would think a "W3JDR" would know that even harmonics are *much*
harder to obtain in nonlinear multipliers.

I guessed I missed Jim's comment in the earlier post, or I would have replied earlier.
Jim, I'm not not sure what you're trying to say, but there seems to be a sarcastic undertone to the way you said it.

Only mildly so, just "funning" you ;-)


Anyway, it turns out that non-linear single-ended elements are great generators of even-order harmonics. That's why the classical HF/VHF multiplier circuit is typically a single ended transistor amplifier with output and input tuned to different frequencies. If you bias the device so it is non-linear, then it becomes a natural harmonic generator. You can enhance even-order generation and supress the odd-order generation by using a non-linear 'push-push' stage, just as you can suppress even order harmonics with a 'push-pull' stage.

In either case, the important thing to remember is that symmetrical clipping or limiting generates mostly odd-order distortion and unsymmetrical clipping or limiting generates mostly even order distortion. The quantification of this is left to those more mathematically inclined.

Joe
W3JDR

It depends on what your are starting from. If it's a sine wave, yes
even harmonics can be made from diode non-linearities.

The OP has a inverter-style XTAL oscillator, output very nearly
square.

A square wave is rich in odd harmonics, a perfect square wave has NO
even harmonics.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

It depends on what your are starting from. If it's a sine wave, yes
even harmonics can be made from diode non-linearities.

The OP has a inverter-style XTAL oscillator, output very nearly
square.

A square wave is rich in odd harmonics, a perfect square wave has NO
even harmonics.



Oh! I see what you're talking about...
I presumed that he was starting with a single spectral component (sine wave) and wanted to end up with another single spectral component.


Joe
W3JDR

It depends on what your are starting from. If it's a sine wave, yes
even harmonics can be made from diode non-linearities.

The OP has a inverter-style XTAL oscillator, output very nearly
square.

A square wave is rich in odd harmonics, a perfect square wave has NO
even harmonics.



Oh! I see what you're talking about...
I presumed that he was starting with a single spectral component (sine wave) and wanted to end up with another single spectral component.


Joe
W3JDR

On Mon, 16 Feb 2004 11:40:18 -0500, " Uncle Peter"
wrote:


"Jim Thompson" wrote in message
.. .
On Mon, 16 Feb 2004 00:18:49 GMT, "W3JDR" wrote:

I would think a "W3JDR" would know that even harmonics are *much*
harder to obtain in nonlinear multipliers.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |


One would think a "PE" could give the man a civil answer.

---
Jim's not a civil engineer...

--
John Fields