BJT VHF frequency doubler circuits

K

Kevin Doyle

Guest
hi all,
I was wondering if anyone has a circuit design for a simple VHF frequency
doubler.

cheers,
Kevin.
 
Great!
Do you know if a 2 pole low pass filter set above the desired freq would
sufice to cut out the harmonics generated by the over drivin stage?

Kevin.
"Mark" <makolber@yahoo.com> wrote in message
news:1119837391.455872.297610@z14g2000cwz.googlegroups.com...
Kevin Doyle wrote:
hi all,
I was wondering if anyone has a circuit design for a simple VHF
frequency
doubler.

cheers,
Kevin.

overdrive a transistor so it is non-linear and tune the output tank to
the desired output freq.

Mark
 
On 26 Jun 2005 18:56:31 -0700, "Mark" <makolber@yahoo.com> wrote:

Kevin Doyle wrote:
hi all,
I was wondering if anyone has a circuit design for a simple VHF frequency
doubler.

cheers,
Kevin.

overdrive a transistor so it is non-linear and tune the output tank to
the desired output freq.

Mark
Over-driving a transistor gives output rich in ODD harmonics.

An ordinary diff pair driven just right produces a nice second-order
component... see the harmonic mixer patent on my website.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.
 
good point! I was think square wave rich in odd harmonics.. for EVEN you
need asymmetry about the time access..wave form shape.

A fet based unit pumping on a varactor load would distort nicely.

as for # poles... more poles will suppress the fundamental and thirds etc..
so you need to know how clean you need..

Marco

"Jim Thompson" <thegreatone@example.com> wrote in message
news:ppnub114sum5lluv8arnp0jog7kom8p7n3@4ax.com...
On 26 Jun 2005 18:56:31 -0700, "Mark" <makolber@yahoo.com> wrote:



Kevin Doyle wrote:
hi all,
I was wondering if anyone has a circuit design for a simple VHF
frequency
doubler.

cheers,
Kevin.

overdrive a transistor so it is non-linear and tune the output tank to
the desired output freq.

Mark

Over-driving a transistor gives output rich in ODD harmonics.

An ordinary diff pair driven just right produces a nice second-order
component... see the harmonic mixer patent on my website.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)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, 27 Jun 2005 03:02:40 +0100, Kevin Doyle top-posted:

Great!
Do you know if a 2 pole low pass filter set above the desired freq would
sufice to cut out the harmonics generated by the over drivin stage?
Geez! Just make a tuned circuit at the target frequency, and let the
harmonics go to the bit bucket! Fr = 1/(2 * pi * sqrt(L * C)).

Good Luck!
Rich
[and I've heard that top-posting is frowned upon amongst da prose.]

Kevin.
"Mark" <makolber@yahoo.com> wrote in message
news:1119837391.455872.297610@z14g2000cwz.googlegroups.com...


Kevin Doyle wrote:
hi all,
I was wondering if anyone has a circuit design for a simple VHF
frequency
doubler.

cheers,
Kevin.

overdrive a transistor so it is non-linear and tune the output tank to
the desired output freq.

Mark
 

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