any US weapons tech that is used outside the US has its IP owned by the State Dept - its cut and dried
within the US its owned by the US company
F-35 Program - General Discussion
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within the US its owned by the US company
You might find this interesting. Aside from functioning as an X-band radar, AESA tech has the potential to support broadband jamming over a wide range of frequencies from 2-20GHz. Note that the patent was filed in Feb 1987 so it would come as no surprise if designers exploited this capability in both the APG-77/and APG-81. Not that they would talk about it of course.
Patent US4823136 - Transmit-receive means for phased-array active antenna system using rf ... - Google Patents
The transmit-receive cells are fully functional at broadband and narrow band radio frequencies. In the narrow band of 9.2 to 10.2 GHz, the active antenna system would operate as a radar system. In the broadband range of 2.0 GHz to 20.0 GHz the active antenna system is fully functional in electronic countermeasures and radio frequency jamming. Either application would find a place on an advanced aircraft or space based sensor systems because of weight and size restrictions.
Boagrius
Well-Known Member
Now that IS fascinating. It has become a catch-cry of the anti-JSF crowd to cite the APG81 as a strictly X-Band radar that is incapable of jamming anything outside of that part of the RF spectrum. As usual, it seems there is much more to the reality of the situation than meets the (civillian/public) eye. Thanks for this, much appreciated.
EDIT: Makes you wonder what applications this sort of thing may already have on a platform like the APG79 equipped Growler... Interesting stuff!
Boagrius
Well-Known Member
For those interested, there is a YouTube series on the F35 that - as best as I can tell as a humble civillian - does a pretty good job of dispelling a lot of the mythology out there about the jet. It has just been updated with a 4th instalment today:
F35 Busting Myths
Enjoy!
F35 Busting Myths
Enjoy!
In a ceremony attended by more than 400 guests from both governments, militaries, and defense industries, Japanese and U.S. government officials celebrated the roll out of the first Japan Air Self Defense Force (JASDF) F-35A Lightning II on Friday, marking a major milestone in Japan’s national defense.
Lockheed Martin and Japan roll out first F-35A for the Japan Air Self Defense Force
Lockheed Martin and Japan roll out first F-35A for the Japan Air Self Defense Force
warning for others.....
don't read the comments unless you want to become numb with disbelief
Boagrius
Well-Known Member
Sage advice when it comes to YouTube in general I suspect!warning for others.....
don't read the comments unless you want to become numb with disbelief
t68
Well-Known Member
Engine fire in an F35A, will be an investigation for the cause, thankfully no one hurt.
F-35A Catches Fire at Mountain Home Air Force Base | Defense News
F-35A Catches Fire at Mountain Home Air Force Base | Defense News
NGJ will benefit from significantly more powerful GaN-based AESA tech. APG-79, -77 and -81 would still be GaAs-based AFAIK but I think it reasonable that these radars will be refreshed with GaN T/Rs down the road.Now that IS fascinating. It has become a catch-cry of the anti-JSF crowd to cite the APG81 as a strictly X-Band radar that is incapable of jamming anything outside of that part of the RF spectrum. As usual, it seems there is much more to the reality of the situation than meets the (civillian/public) eye. Thanks for this, much appreciated.
EDIT: Makes you wonder what applications this sort of thing may already have on a platform like the APG79 equipped Growler... Interesting stuff!
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bakers dozen slated for return to business in the near future:
Avionics Magazine :: 13 USAF F-35s Taken out of Service Could Return to Operations This Year
Avionics Magazine :: 13 USAF F-35s Taken out of Service Could Return to Operations This Year
That series is put up by Dragon029, who is a prolific poster on Reddit and f-16.net and is pretty knowledgeable about the F-35. IIRC it basically stems from having to correct the same myths and misinformation on Reddit and other websites all day.
I often use these as a starting point for people to debunk the misinformation that has been bandied about by News Corp. and others.
Boagrius
Well-Known Member
Further to the question of the F35's jamming capabilities, I stumbled upon this brochure from BAE:
http://www.baesystems.com/en-us/download-en-us/20160718215911/1434583878736.pdf
Second page clearly depicts an "aperture" used in the Barracuda system which must surely be an emitter of some sort (?) Not educated enough to say whether this would be part of an integrated SPJ type emitter setup or perhaps a towed decoy (maybe AN/ALE70).
Either way the idea that the F35 can only emit in the X-Band via the APG81 for jamming/EW purposes (*cough*APA*cough*Solomon*cough*) seems to be total bunkum, particularly when taken in light of colay's post above.
EDIT:
A recent ad from the manufacturer showing the same components:
https://www.youtube.com/watch?v=DeJAnQgd5m8
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^unfortunately you can't really tell if an aperture/antenna is used for transmit, receive, or both as the reciprocity property of antennas requires this symmetry (ie. radiation or lobe pattern is equivalent in transmission and reception except for direction of propagation)...
you'ld need to see what was connected to the antenna, eg. is there a exciter/transmitter, tx-element, etc., to say if it was used for transmission... (note I'm not saying this particular asq239 antenna isn't used to transmit, it might be used for both, or either exclusively depending on what was connected to it)...
you'ld need to see what was connected to the antenna, eg. is there a exciter/transmitter, tx-element, etc., to say if it was used for transmission... (note I'm not saying this particular asq239 antenna isn't used to transmit, it might be used for both, or either exclusively depending on what was connected to it)...
Boagrius
Well-Known Member
Fair enough. That said I have heard the suggestion on other fora that it resembles a Vivaldi antenna:
https://i.imgur.com/QrU73RA.png
...along with the spotting of what might be a towed decoy bay (bottom right ??):
Pic 1
Pic 2
^a vivaldi antenna also follows the reciprocity property, hence it can be used for transmit, or receive, or both, depending on what is connected to the antenna...
for example here is an application of a vivaldi antenna array for receive purposes (in this case radio astronomy): http://www.ece.ualberta.ca/~kambiz/papers/J11.pdf
while here is an example of an application using vivaldi antenna arrays for both transmission and reception (in this case for ultra-wideband see-through-wall use): http://onlinewww.jpier.org/PIER/pier82/26.08040601.pdf
so what is connected to the vivaldi antenna determines whether it is used to receive or transmit or both...
for example here is an application of a vivaldi antenna array for receive purposes (in this case radio astronomy): http://www.ece.ualberta.ca/~kambiz/papers/J11.pdf
while here is an example of an application using vivaldi antenna arrays for both transmission and reception (in this case for ultra-wideband see-through-wall use): http://onlinewww.jpier.org/PIER/pier82/26.08040601.pdf
so what is connected to the vivaldi antenna determines whether it is used to receive or transmit or both...
AFAIK, it is still uncertain whether the F-35 has a Fibre Optic Towed Decoy system or uses an expendable decoy system, but that is what that bay is for, yes.
Boagrius
Well-Known Member
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This. Confirmation that the ALE 70 Towed Decoy is integrated with the F-35.
http://www.dtic.mil/procurement/Y2017/AirForce/U_P40_76_BSA-4_BA-7_APP-3010F_PB_2017.pdf