I came across this gorgeous distributed element filter yesterday, but nobody knows exactly what it came out of. My take is that it's probably something along the lines of a radar or a millimeter wave scanner, given that it looks like there's a transmit and receive antenna in each of the cavities, but maybe that's unrelated - both transmit or both receive, but 90* polarization to each other. Maybe the latter makes more sense- all the paths look quite similar, but then I don't know enough about RF that I could likely tell a transmit side from a receive unless Tx was coming straight out of a marked RF power amp IC. Someone DID tell me that given the particular junk drawer it came out of, it's more likely to be civilian than military.
Anyway, does anyone with more RF experience than myself know with any confidence what this is actually from? The filters are just gorgeous. The two ICs on the bottom are marked (I think) IX2458/315A and 78F9116A/0447L811
EDIT: it looks like the second marked part I listed (78F9116A, closest to the left of the board in the first couple shots) is a generic NEC microcontroller.
http://www.datasheet-pdf.com/datasheet/NEC/554121/78F9116A.pdf.html