800MHz signal source...

  • Thread starter Klaus Vestergaard Kragelund
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Klaus Vestergaard Kragelund

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Hi

For an upcoming project, I need to generate a 800MHz signal that is used
as an energy source for a energy harvesting solution

So far I have been told it\'s a 800MHz burst, so looks something like this:

https://static-01.hindawi.com/articles/ddns/volume-2011/569141/figures/569141.fig.001c.jpg

I do not know the repetition rate

I have 2 500MHz DDS signal generators. I am thinking maybe feeding them
to a mixer and using a bandpass to only get the 800MHz signal.

Does that sound reasonable?

I could also use a FET open drain to charge an inductor and let a
capacitor trim the LC resonant frequency. A lot easier probably

Regards

Klaus
 
Klaus Vestergaard Kragelund <klauskvik@hotmail.com> wrote:

I could also use a FET open drain to charge an inductor and let a
capacitor trim the LC resonant frequency. A lot easier probably
Click to expand...

That sounds much more reasonable. You could trim the Q to get the desired
decay rate. That would be difficult to do with DDS generators. BTW, what DDS
generators do you use to reach 500MHz?



--
MRM
 
On Saturday, August 27, 2022 at 1:33:39 PM UTC-7, Klaus Kragelund wrote:
Hi

For an upcoming project, I need to generate a 800MHz signal that is used
as an energy source for a energy harvesting solution

So far I have been told it\'s a 800MHz burst, so looks something like this:

https://static-01.hindawi.com/articles/ddns/volume-2011/569141/figures/569141.fig.001c.jpg

I do not know the repetition rate

I have 2 500MHz DDS signal generators. I am thinking maybe feeding them
to a mixer and using a bandpass to only get the 800MHz signal.
Click to expand...

Could you just use a varactor and triple the DDS output frequency? Triplers
were a common item once-upon-a-time, and it oughtn\'t be too hard to get a
generator of 267 MHz.

It even works at high frequency
<https://ntrs.nasa.gov/citations/19940000320>
 
On a sunny day (Sat, 27 Aug 2022 22:33:21 +0200) it happened Klaus Vestergaard
Kragelund <klauskvik@hotmail.com> wrote in <tedv2e$v7c$1@gioia.aioe.org>:

Hi

For an upcoming project, I need to generate a 800MHz signal that is used
as an energy source for a energy harvesting solution

So far I have been told it\'s a 800MHz burst, so looks something like this:

https://static-01.hindawi.com/articles/ddns/volume-2011/569141/figures/569141.fig.001c.jpg

I do not know the repetition rate

I have 2 500MHz DDS signal generators. I am thinking maybe feeding them
to a mixer and using a bandpass to only get the 800MHz signal.

Does that sound reasonable?

I could also use a FET open drain to charge an inductor and let a
capacitor trim the LC resonant frequency. A lot easier probably

Regards

Klaus
Click to expand...

LC oscillators work OK at 800 MHz, even for high power.
You could AM modulate its supply perhaps?
 
On 2022-08-28 08:27, Jan Panteltje wrote:
On a sunny day (Sat, 27 Aug 2022 22:33:21 +0200) it happened Klaus Vestergaard
Kragelund <klauskvik@hotmail.com> wrote in <tedv2e$v7c$1@gioia.aioe.org>:

Hi

For an upcoming project, I need to generate a 800MHz signal that is used
as an energy source for a energy harvesting solution

So far I have been told it\'s a 800MHz burst, so looks something like this:

https://static-01.hindawi.com/articles/ddns/volume-2011/569141/figures/569141.fig.001c.jpg

I do not know the repetition rate

I have 2 500MHz DDS signal generators. I am thinking maybe feeding them
to a mixer and using a bandpass to only get the 800MHz signal.

Does that sound reasonable?

I could also use a FET open drain to charge an inductor and let a
capacitor trim the LC resonant frequency. A lot easier probably

Regards

Klaus

LC oscillators work OK at 800 MHz, even for high power.
You could AM modulate its supply perhaps?
Click to expand...

Nothing is said about the required power level. I would try to ping
an 800MHz LC resonator with a transistor switch. Much simpler than
DDSs, mixers and filters.

Jeroen Belleman
 
lørdag den 27. august 2022 kl. 22.33.39 UTC+2 skrev Klaus Kragelund:
Hi

For an upcoming project, I need to generate a 800MHz signal that is used
as an energy source for a energy harvesting solution

So far I have been told it\'s a 800MHz burst, so looks something like this:

https://static-01.hindawi.com/articles/ddns/volume-2011/569141/figures/569141.fig.001c.jpg

I do not know the repetition rate

I have 2 500MHz DDS signal generators. I am thinking maybe feeding them
to a mixer and using a bandpass to only get the 800MHz signal.

Does that sound reasonable?

I could also use a FET open drain to charge an inductor and let a
capacitor trim the LC resonant frequency. A lot easier probably
Click to expand...

how sketchy do you want? https://www.ebay.com/itm/184438216383
 
On 28-08-2022 04:07, Mike Monett VE3BTI wrote:
Klaus Vestergaard Kragelund <klauskvik@hotmail.com> wrote:

I could also use a FET open drain to charge an inductor and let a
capacitor trim the LC resonant frequency. A lot easier probably


That sounds much more reasonable. You could trim the Q to get the desired
decay rate. That would be difficult to do with DDS generators. BTW, what DDS
generators do you use to reach 500MHz?
Click to expand...
I have the Siglent SDG6022X, hacked to go to 500MHz (very very good
price performance ratio)
 
On 28-08-2022 12:02, Lasse Langwadt Christensen wrote:
lørdag den 27. august 2022 kl. 22.33.39 UTC+2 skrev Klaus Kragelund:
Hi

For an upcoming project, I need to generate a 800MHz signal that is used
as an energy source for a energy harvesting solution

So far I have been told it\'s a 800MHz burst, so looks something like this:

https://static-01.hindawi.com/articles/ddns/volume-2011/569141/figures/569141.fig.001c.jpg

I do not know the repetition rate

I have 2 500MHz DDS signal generators. I am thinking maybe feeding them
to a mixer and using a bandpass to only get the 800MHz signal.

Does that sound reasonable?

I could also use a FET open drain to charge an inductor and let a
capacitor trim the LC resonant frequency. A lot easier probably


how sketchy do you want? https://www.ebay.com/itm/184438216383
Click to expand...
Nice, I am guessing that is only digital output...
 
On 28-08-2022 11:45, Jeroen Belleman wrote:
On 2022-08-28 08:27, Jan Panteltje wrote:
On a sunny day (Sat, 27 Aug 2022 22:33:21 +0200) it happened Klaus
Vestergaard
Kragelund <klauskvik@hotmail.com> wrote in <tedv2e$v7c$1@gioia.aioe.org>:

Hi

For an upcoming project, I need to generate a 800MHz signal that is used
as an energy source for a energy harvesting solution

So far I have been told it\'s a 800MHz burst, so looks something like
this:

https://static-01.hindawi.com/articles/ddns/volume-2011/569141/figures/569141.fig.001c.jpg


I do not know the repetition rate

I have 2 500MHz DDS signal generators. I am thinking maybe feeding them
to a mixer and using a bandpass to only get the 800MHz signal.

Does that sound reasonable?

I could also use a FET open drain to charge an inductor and let a
capacitor trim the LC resonant frequency. A lot easier probably

Regards

Klaus

LC oscillators work OK at 800 MHz, even for high power.
You could AM modulate its supply perhaps?


Nothing is said about the required power level. I would try to ping
an 800MHz LC resonator with a transistor switch. Much simpler than
DDSs, mixers and filters.
Click to expand...
Yes, seems to be the way forward
 
Klaus Vestergaard Kragelund <klauskvik@hotmail.com> wrote:

On 28-08-2022 04:07, Mike Monett VE3BTI wrote:
Klaus Vestergaard Kragelund <klauskvik@hotmail.com> wrote:

I could also use a FET open drain to charge an inductor and let a
capacitor trim the LC resonant frequency. A lot easier probably


That sounds much more reasonable. You could trim the Q to get the
desired decay rate. That would be difficult to do with DDS generators.
BTW, what DDS generators do you use to reach 500MHz?



I have the Siglent SDG6022X, hacked to go to 500MHz (very very good
price performance ratio)
Click to expand...

That\'s some hack!



--
MRM
 
On 8/27/2022 3:33 PM, Klaus Vestergaard Kragelund wrote:
Hi

For an upcoming project, I need to generate a 800MHz signal that is
used as an energy source for a energy harvesting solution

So far I have been told it\'s a 800MHz burst, so looks something like
this:

https://static-01.hindawi.com/articles/ddns/volume-2011/569141/figures/569141.fig.001c.jpg


I do not know the repetition rate

I have 2 500MHz DDS signal generators. I am thinking maybe feeding
them to a mixer and using a bandpass to only get the 800MHz signal.

Does that sound reasonable?

I could also use a FET open drain to charge an inductor and let a
capacitor trim the LC resonant frequency. A lot easier probably

Regards

Klaus
Click to expand...
 Can you adjust the values of this odd harmonic generator?
Charles Wenzel, \'New Topology Multipier Generates Odd Harmonics\'
> http://techlib.com/files/RFDesign2.pdf
                      Mikek
 I don\'t know about a decaying burst.
 
On Sat, 27 Aug 2022 22:33:21 +0200, Klaus Vestergaard Kragelund
<klauskvik@hotmail.com> wrote:

Hi

For an upcoming project, I need to generate a 800MHz signal that is used
as an energy source for a energy harvesting solution

So far I have been told it\'s a 800MHz burst, so looks something like this:

https://static-01.hindawi.com/articles/ddns/volume-2011/569141/figures/569141.fig.001c.jpg

I do not know the repetition rate

I have 2 500MHz DDS signal generators. I am thinking maybe feeding them
to a mixer and using a bandpass to only get the 800MHz signal.

Does that sound reasonable?

I could also use a FET open drain to charge an inductor and let a
capacitor trim the LC resonant frequency. A lot easier probably

Regards

Klaus
Click to expand...

Get a hold of the actual intended generator hardware, or its current
prototype.

RL
 
On Saturday, August 27, 2022 at 1:33:39 PM UTC-7, Klaus Kragelund wrote:
I have 2 500MHz DDS signal generators. I am thinking maybe feeding them
to a mixer and using a bandpass to only get the 800MHz signal.
Click to expand...

Tune one of the generators to 200 MHz and use an 800 MHz BPF instead
of a <250 MHz LPF as the DAC output filter? Most DDS chips put out
a useful signal well into the GHz range, as long as you steer clear of
the sinc nulls.

-- john, KE5FX
 
Klaus Vestergaard Kragelund wrote:
Hi

For an upcoming project, I need to generate a 800MHz signal that is used
as an energy source for a energy harvesting solution

So far I have been told it\'s a 800MHz burst, so looks something like this:

https://static-01.hindawi.com/articles/ddns/volume-2011/569141/figures/569141.fig.001c.jpg


I do not know the repetition rate

I have 2 500MHz DDS signal generators. I am thinking maybe feeding them
to a mixer and using a bandpass to only get the 800MHz signal.

Does that sound reasonable?

I could also use a FET open drain to charge an inductor and let a
capacitor trim the LC resonant frequency. A lot easier probably

Regards

Klaus
Click to expand...

For a one-off, I\'d tend to go with a Mini Circuits FD-2 frequency
doubler from my drawer, followed by a BPF made from coax stubs.

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
 
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

Klaus Vestergaard Kragelund wrote:
Hi

For an upcoming project, I need to generate a 800MHz signal that is
used as an energy source for a energy harvesting solution

So far I have been told it\'s a 800MHz burst, so looks something like
this:

https://static-01.hindawi.com/articles/ddns/volume-2011/569141/figures/5
69141.fig.001c.jpg


I do not know the repetition rate

I have 2 500MHz DDS signal generators. I am thinking maybe feeding them
to a mixer and using a bandpass to only get the 800MHz signal.

Does that sound reasonable?

I could also use a FET open drain to charge an inductor and let a
capacitor trim the LC resonant frequency. A lot easier probably

Regards

Klaus

For a one-off, I\'d tend to go with a Mini Circuits FD-2 frequency
doubler from my drawer, followed by a BPF made from coax stubs.

Cheers

Phil Hobbs
Click to expand...

How do you get the exponential decay?



--
MRM
 
On Monday, 29 August 2022 at 15:31:49 UTC+1, Mike Monett VE3BTI wrote:
Phil Hobbs <pcdhSpamM...@electrooptical.net> wrote:

Klaus Vestergaard Kragelund wrote:
Hi

For an upcoming project, I need to generate a 800MHz signal that is
used as an energy source for a energy harvesting solution

So far I have been told it\'s a 800MHz burst, so looks something like
this:

https://static-01.hindawi.com/articles/ddns/volume-2011/569141/figures/5
69141.fig.001c.jpg


I do not know the repetition rate

I have 2 500MHz DDS signal generators. I am thinking maybe feeding them
to a mixer and using a bandpass to only get the 800MHz signal.

Does that sound reasonable?

I could also use a FET open drain to charge an inductor and let a
capacitor trim the LC resonant frequency. A lot easier probably

Regards

Klaus

For a one-off, I\'d tend to go with a Mini Circuits FD-2 frequency
doubler from my drawer, followed by a BPF made from coax stubs.

Cheers

Phil Hobbs
How do you get the exponential decay?
Click to expand...
More to the point, how does a power transfer device operating with
that type of waveform and frequency stand any chance of getting
regulatory approval?
John
 
On Mon, 29 Aug 2022 14:31:41 -0000 (UTC), Mike Monett VE3BTI
<spamme@not.com> wrote:

Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

Klaus Vestergaard Kragelund wrote:
Hi

For an upcoming project, I need to generate a 800MHz signal that is
used as an energy source for a energy harvesting solution

So far I have been told it\'s a 800MHz burst, so looks something like
this:

https://static-01.hindawi.com/articles/ddns/volume-2011/569141/figures/5
69141.fig.001c.jpg


I do not know the repetition rate

I have 2 500MHz DDS signal generators. I am thinking maybe feeding them
to a mixer and using a bandpass to only get the 800MHz signal.

Does that sound reasonable?

I could also use a FET open drain to charge an inductor and let a
capacitor trim the LC resonant frequency. A lot easier probably

Regards

Klaus

For a one-off, I\'d tend to go with a Mini Circuits FD-2 frequency
doubler from my drawer, followed by a BPF made from coax stubs.

Cheers

Phil Hobbs

How do you get the exponential decay?
Click to expand...

The problem is under-defined.
 
Mike Monett VE3BTI wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

Klaus Vestergaard Kragelund wrote:
Hi

For an upcoming project, I need to generate a 800MHz signal that is
used as an energy source for a energy harvesting solution

So far I have been told it\'s a 800MHz burst, so looks something like
this:

https://static-01.hindawi.com/articles/ddns/volume-2011/569141/figures/5
69141.fig.001c.jpg


I do not know the repetition rate

I have 2 500MHz DDS signal generators. I am thinking maybe feeding them
to a mixer and using a bandpass to only get the 800MHz signal.

Does that sound reasonable?

I could also use a FET open drain to charge an inductor and let a
capacitor trim the LC resonant frequency. A lot easier probably

Regards

Klaus

For a one-off, I\'d tend to go with a Mini Circuits FD-2 frequency
doubler from my drawer, followed by a BPF made from coax stubs.

Cheers

Phil Hobbs

How do you get the exponential decay?
Click to expand...

By switching off the incoming RF and letting the filter ring, or by
making the envelope at baseband and running it into the IF port of a mixer.

Mixers and RF switches are also in the MCL catalogue, as are suitable
amplifiers. Old RF guys usually have a drawer full of that sort of
stuff, which is great for one-offs.

I\'ve also used medium-power amps from RF Bay, which gave great bang for
the buck.

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
 
On 29-08-2022 17:39, John Walliker wrote:
On Monday, 29 August 2022 at 15:31:49 UTC+1, Mike Monett VE3BTI wrote:
Phil Hobbs <pcdhSpamM...@electrooptical.net> wrote:

Klaus Vestergaard Kragelund wrote:
Hi

For an upcoming project, I need to generate a 800MHz signal that is
used as an energy source for a energy harvesting solution

So far I have been told it\'s a 800MHz burst, so looks something like
this:

https://static-01.hindawi.com/articles/ddns/volume-2011/569141/figures/5
69141.fig.001c.jpg


I do not know the repetition rate

I have 2 500MHz DDS signal generators. I am thinking maybe feeding them
to a mixer and using a bandpass to only get the 800MHz signal.

Does that sound reasonable?

I could also use a FET open drain to charge an inductor and let a
capacitor trim the LC resonant frequency. A lot easier probably

Regards

Klaus

For a one-off, I\'d tend to go with a Mini Circuits FD-2 frequency
doubler from my drawer, followed by a BPF made from coax stubs.

Cheers

Phil Hobbs
How do you get the exponential decay?

More to the point, how does a power transfer device operating with
that type of waveform and frequency stand any chance of getting
regulatory approval?
John
Click to expand...

I am not fully into the details yet.

But for other projects, to get RED approval for contactless charger,
either use the excemption band, or apply fully magnetic shielding (so
both part mate, and closes a magnetic path)
 
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

How do you get the exponential decay?




By switching off the incoming RF and letting the filter ring, or by
making the envelope at baseband and running it into the IF port of a
mixer.

Mixers and RF switches are also in the MCL catalogue, as are suitable
amplifiers. Old RF guys usually have a drawer full of that sort of
stuff, which is great for one-offs.

I\'ve also used medium-power amps from RF Bay, which gave great bang for
the buck.

Cheers

Phil Hobbs
Click to expand...

That would work if there is only one tuned circuit in the path. What would
happen if there were multiple tuned circuits? The Radiotron Designer\'s
Handbook might give some clues.



--
MRM
 
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