How to tune a 20ghz filter to 24ghz ??


John Lambo
 

Hello microwavers
I got form e-bay a 20 ghz LNB
What i like to know is:
I wonder does any one try to tune this strip line filter from 20 ghz to 24ghz ??
And also what will happend if i put a other dro in the oscillator and try to get it wroking on 23ghz or beter to say 11,5 ghz.
Thank you for reply .

73 John PA7JB


DougF VK4OE
 

Hello John and other readers.

Regarding the possibility of re-tuning a 20 GHz stripline filter (presumably "microstrip"!) that far up in frequency, my experience is that it is probably a "tall ask". It might just be possible, but removing parts of the filter elements will cause significant 'damage' to the originally designed performance parameters, meaning that the final result may have worse insertion loss, bandwidth and input/output impedance. If you're willing to risk that outcome, by all means give modification a go....but you'll probably have only ever one chance at being successful! And, my experience is that it's far easier to bring 'microstrip' filters down in frequency than it is to raise their operating frequency.....

With your question about the DRO, I don't have any experience with replacing DRO pucks. Hopefully someone else will comment. But are you talking about free-running DROs which have doubtful usability except for wideband FM operation, or are you talking about DROs that are locked to a stable reference oscillator?

Very best wishes,

--Doug Friend, VK4OE.

On 13/07/2013 8:55 PM, John Lambo wrote:
Hello microwavers
I got form e-bay a 20 ghz LNB
What i like to know is:
I wonder does any one try to tune this strip line filter from 20 ghz to
24ghz ??
And also what will happend if i put a other dro in the oscillator and
try to get it wroking on 23ghz or beter to say 11,5 ghz.
Thank you for reply .

73 John PA7JB


John Lambo
 

Hello Doug and others
Yes it is a micorstrip filter en very small ;-))
I will try what i can do..

73 John PA7JB



Op 13-7-2013 13:34, DougF schreef:

Hello John and other readers.

Regarding the possibility of re-tuning a 20 GHz stripline filter
(presumably "microstrip"!) that far up in frequency, my experience is
that it is probably a "tall ask". It might just be possible, but
removing parts of the filter elements will cause significant 'damage' to
the originally designed performance parameters, meaning that the final
result may have worse insertion loss, bandwidth and input/output
impedance. If you're willing to risk that outcome, by all means give
modification a go....but you'll probably have only ever one chance at
being successful! And, my experience is that it's far easier to bring
'microstrip' filters down in frequency than it is to raise their
operating frequency.....

With your question about the DRO, I don't have any experience with
replacing DRO pucks. Hopefully someone else will comment. But are you
talking about free-running DROs which have doubtful usability except for
wideband FM operation, or are you talking about DROs that are locked to
a stable reference oscillator?

Very best wishes,

--Doug Friend, VK4OE.

On 13/07/2013 8:55 PM, John Lambo wrote:
Hello microwavers
I got form e-bay a 20 ghz LNB
What i like to know is:
I wonder does any one try to tune this strip line filter from 20 ghz to
24ghz ??
And also what will happend if i put a other dro in the oscillator and
try to get it wroking on 23ghz or beter to say 11,5 ghz.
Thank you for reply .

73 John PA7JB

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