making a frequency doubler circuit, want another set of eyes on it

[Halcyon]

Do not expect people will be elaborating pretty obvious stuff.. 

You're going on my ignore list for being a deliberately unhelpful dickhead.

Whether you personally think someone is a dickhead or not, how is it appropriate, particularly as a new member to post such a comment?

[Kyle_from_somewhere]

It's simple honesty. I think even people who've annoyed me enough that I don't want to ever speak to them again deserve honesty. I also don't think being a "new member" or an "old member" counts for anything. Do you pay pensions?

I could ask how it is appropriate for someone who fancies himself a moderator to participate in derailing a thread after efforts have been made to put it back on track.

[Halcyon]

It's simple honesty. I think even people who've annoyed me enough that I don't want to ever speak to them again deserve honesty.

I could ask how it is appropriate for someone who fancies himself a moderator to participate in derailing a thread after efforts have been made to put it back on track.

Then please keep it private. If you want to call someone a dickhead to their face, then do that, but don't do it out in the open for everyone to see. You just get everyone else off-side and then you become the dickhead (rightly or wrongly). I've read some of your posts and they do tend to be a little on the hostile side. It's not a way to get what you want in this kind of environment and as you have already seen, some people like to stir the pot simply to get a rise out of you for entertainment.

This goes for everyone, not just you: Let's be a little more respectful and keep the snide comments down.

As for my involvement, I did so because your posts have been reported by members of this forum and contributors to this thread. If you don't like the way I operate, tough luck. This is not a time for you to start pointing fingers at others, this is specifically about you and your conduct.

[Kyle_from_somewhere]

It's pretty hypocritical of you to come into my thread and talk shit about me publicly while also telling me to only talk shit to someone in private.

You would be a better moderator if you tried leading by example, rather than this "do as I say, not as I do" routine, the tired schtick of drunken domestic abusers everywhere.

If you don't like me discussing how you operate, tough luck. You asked for it, and I always give as I've gotten.

[Jay_Diddy_B]

Hi,
To solve one of the LTspice modelling issues. This is how to add the DI_1N5711 diode to your simulation:



This is how you add a SPICE directive:



This is the best way, in my opinion, the model is now part of the schematic.

I have attached the model.

Regards,

Jay_Diddy_B

[Kyle_from_somewhere]

Hi,
To solve one of the LTspice modelling issues. This is how to add the DI_1N5711 diode to your simulation:



This is how you add a SPICE directive:



This is the best way, in my opinion, the model is now part of the schematic.

I have attached the model.

Regards,

Jay_Diddy_B

Thank you, that helps a lot.

[Halcyon]

It's pretty hypocritical of you to come into my thread and talk shit about me publicly while also telling me to only talk shit to someone in private.

You would be a better moderator if you tried leading by example, rather than this "do as I say, not as I do" routine, the tired schtick of drunken domestic abusers everywhere.

If you don't like me discussing how you operate, tough luck. You asked for it, and I always give as I've gotten.

Firstly, this is not your thread. This is Dave's forum and he has empowered a few of us to ensure that his expectations and rules are upheld. Like most things in life, if you choose to breach those rules, there are consequences. I think most people here will agree that the moderators here are pretty easy-going and this is one of the least moderated forums out there. But when people come here and start causing trouble, then we need to step in (particularly as other users have asked us to). Because you don't agree with it, doesn't make it an abuse of power. Either way, you simply don't have a choice in this matter.

I think most of the people in this thread would have accepted an apology from you at this point, but you chose to keep carrying-on like a pork chop. Since you seem to respond to honesty, allow me to be blunt: Pull your head in, or you will be removed from this forum.

Now which will it be? The red pill or the blue pill?

[Kyle_from_somewhere]

I've never heard of any dave. Am I supposed to be impressed you know a guy named dave? That's possibly the least amount of power anyone has ever gone mad with.

Make those other guys apologize to me, if you can muster that power. I've done nothing wrong whatsoever.

[fourfathom]

.....

Kyle, are you here to learn (or at least get an answer), or are you here for a pissing match?

If the former, start with J_Diddy_B's circuit and see what an isolated diode doubler does.  Then, if you like, start adding amplification and filtering.  This will require some degree of impedance matching.

One thing about the diode doubler, it's going to require a stronger drive level and probably more power than the transistor doublers you started with.  If that's an issue, perhaps your first design is a good starting point.  But it still needs lots of work.

[Kyle_from_somewhere]

I came for answers. People interested in pissing matches asked me for one and I gave it to them out of kindness. One by one they made themselves look like retards, but they wanted that, so it's okay.

[Halcyon]

I came for answers. People interested in pissing matches asked me for one and I gave it to them out of kindness. One by one they made themselves look like retards, but they wanted that, so it's okay.

I think you need to do a little self-reflection and consider the way you speak to people, particularly as you are reaching out for help and assistance with your projects. Getting people off-side and continuing to have the last word as your own hole gets deeper and deeper is not the way to go about it.

In order to help facilitate some of that self-reflection time, I've given you a short ban from posting. Hopefully you return with a little more clarity in a few days.

For everyone else, I apologise for the disruption this user has caused. Thank you to those who reported.

[Jay_Diddy_B]

Hi,

Here is a link to the HP 11721A frequency doubler manual:

https://xdevs.com/doc/HP_Agilent_Keysight/HP%2011721A%20Operating%20&%20Service.pdf

Here is another link with photographs:

https://idewerks.com/2020/03/24/hp-11721a-frequency-doubler-lab-repair/



The circuit is shown as:



The manual says this works best with an input of 13dBm +/- 1dBm.

This can be modeled as:



I have attached the model.

This is not tuned, like many other frequency doublers.

Jay_Diddy_B
 hp 11721A doubler.asc (2.04 kB - downloaded 80 times.)

[mawyatt]

We were going to post a circuit we've utilized well into the many GHz region (with fast SiGe transistors), but because of the OP attitude decided not to provide support.

It involves differential In/Output and 4 transistors configured in a differential quad type. Here's a plot with 2N3904s of the output differential current at 100MHz 200MHz (Input 100MHz) without any tuning network, of course faster transistors as mentioned would be better but the circuit seems to extract the best of the transistors used and why we utilized such in many of our IC designs. The green trace is the differential input voltage and the grey trace is the differential output current without any filtering involved.

Edit: Corrected above and added another plot with Input at 200MHz, Output at 400MHz with 2N3904 devices.

Use a PM if interested in more details.

Best,

[fourfathom]

Here's a plot with 2N3904s of the output differential current at 100MHz without any tuning network

Sounds like a sine-squared multiplier?

I threw together (LTSpice) a push-push doubler using three transistors:  The first stage is a unity-gain amp with collector and emitter providing 0 and 180-degree phase outputs.  These drive two AC-coupled transistors with the collectors connected together and driving a common load.  The output is closer to a full-wave rectifier than your nice sinusoid.  I simulated with 2n3904s and the amplitude was beginning to fall off starting a bit below 100 MHz.  I didn't spend a lot of time tweaking it.  Resistors, capacitors and transistors only, no inductors or tuned circuits.

[Gerhard_dk4xp]

That looks MUCH better than the output doubler of the ADF5356 synthesizer chip.

... and I'm curious for the details     :-)

dk4xp at arcor dot de

Cheers, Gerhard

[mawyatt]

Here's a plot with 2N3904s of the output differential current at 100MHz without any tuning network

Sounds like a sine-squared multiplier?

I threw together (LTSpice) a push-push doubler using three transistors:  The first stage is a unity-gain amp with collector and emitter providing 0 and 180-degree phase outputs.  These drive two AC-coupled transistors with the collectors connected together and driving a common load.  The output is closer to a full-wave rectifier than your nice sinusoid.  I simulated with 2n3904s and the amplitude was beginning to fall off starting a bit below 100 MHz.  I didn't spend a lot of time tweaking it.  Resistors, capacitors and transistors only, no inductors or tuned circuits.

Not sure what it was called, but here's the LTspice schematic and doubler plots. Because of the well controlled current range, lack of device saturation and differential input impedance control this worked well into the many GHz range with fast devices, and easily cascaded using a center tapped transformer on the outputs. Long ago a colleague utilizing something like this for generating 90GHz, then another doubler (this might have been with SB diodes tho) to get to 180GHz, this was in an experimental early IBM SiGe BiCMOS process 9hp.

First plot is 200MHz Output, second is 400MHz Output with 2N3904s.

Best,

[fourfathom]

Not sure what it was called, but here's the LTspice schematic and doubler plots.

That's essentially a push-push doubler. Q4 and Q2 are being driven 180 degrees out of phase and the collectors are tied together (very similar to my PP Doubler, but I used a transistor for the phase inverter instead of the two generators, and a resistor instead of the inductor.  I'm not clear on what the inner transistors Q1 and Q3 are doing -- you can ground those bases and it still works (the two 50 Ohm resistors form a virtual ground), but if you remove Q1 and Q3 the doubled output amplitude drops significantly.  Some sort of V_BE compensation?

Here's a basic transformer-input push-push doubler using 2N904s, 100 MHz input.  Input and output Z *not* 50 Ohms.  It works with 200 MHz input, but the output has fallen by almost 20 dB.

[mawyatt]

I'm not clear on what the inner transistors Q1 and Q3 are doing -- you can ground those bases and it still works (the two 50 Ohm resistors form a virtual ground), but if you remove Q1 and Q3 the doubled output amplitude drops significantly.  Some sort of V_BE compensation?

We used this on many of the RF/MW SoC chips we did back starting in ~2000 as a Square-Law Detector for accurate on-chip RF signal measurements, then a little later as a frequency doubler and also used as a real-time analog signal conditioner where the output current closely approximated a hyperbolic-trigonometeric function (likely the Cosh function) to "equalize" a dynamic signal in real time.

It's been too long and I'm too old remember the finer details and too lazy to do the math

I'm sure one could reverse engineer this and produce the non-linear transfer function finer details if necessary.

Do recall the two center transistors were for compensation and vaguely remember the 4 transistors were located in an Erdi Quad arrangement for temperature and process gradient compensation. Q2 and Q4 did have series resistors to the bases (not shown in first schematic, but redone below with resistors) so the arrangement had all 4 transistors "seeing" similar source impedances, altho none were exactly 50 ohms. This of course made the differential output current almost zero without an input signal, which was a necessary requirement.

Anyway, hope this helps, altho don't feel the OP deserves any help from anyone with the attitude shown, and why we didn't show the schematic earlier.

Edit: Added a couple plots showing Differential Output Current vs. Differential Input Voltage. Fist plot is with Vsource +-20mV and second plot is with Vsource +-200mv. Note, input sources V3 and V4 include 50 ohm impedances.

Best,

[Kyle_from_somewhere]

Hello everyone. First of all I'd like to say that i'm not sorry, you all suck and I am the best. I figured it out on my own, I've got a healthy 6mW stable 480mhz sine. None of you get to see because you dumped shit into my thread and cried like babies to the virginal forum mod when I shoved it back in your faces.

 I found out who that dave is too. I'm surprised he became an engineer, if my son had a voice like that i'd have left him in a hot car and told the police it was an accident.

[Halcyon]

Hello everyone. First of all I'd like to say that i'm not sorry, you all suck and I am the best. I figured it out on my own, I've got a healthy 6mW stable 480mhz sine. None of you get to see because you dumped shit into my thread and cried like babies to the virginal forum mod when I shoved it back in your faces.

 I found out who that dave is too. I'm surprised he became an engineer, if my son had a voice like that i'd have left him in a hot car and told the police it was an accident.

Welcome back Kyle. Good to see you've had time to reflect on your own immaturity and attitude problem. It's a shame that your little ban didn't help in this instance. I guess some people will just continue through life being complete assholes, right?

Since you made the decision to continue acting like a complete tool, as opposed to apologising for your behaviour, I've made the decision to permanently ban you from the forum, so that we don't have to continue reading your garbage. Consider this a life lesson on how you speak to people (you're welcome).

[Gerhard_dk4xp]

You've forgotten a "not" just before welcome.

Gerhard

[Halcyon]

You've forgotten a "not" just before welcome.

Gerhard

I give everyone the benefit of the doubt. But I guess when you have the maturity of a 13 year old, any and all efforts are pointless. I could have been harsher, but why stoop to his level?