MEMS relays

Vacuum tubes?

--
.
.
.
.
.
.
.
.

well, it must be small, i need plenty of them on PCB... tubes have quite poor isolation for RF, and take too much space. Their lifetime is also quite low - it must work for a few years.

Your operating rate and desired lifetime imply an operating life of at least

10^8 cycles, maybe more. Are you hot-switching? If so, how much current? This is the death of relays, especially MEMS ones. And last I heard MEMS relay lifetimes were still in the 10^7--10^8 range under cold-switching conditions, so you may not find what you want just yet.

How about CMOS-on-Silicon? Does it still exist? It was developed for military usage and space, so perhaps the radiation wouldn't be too troublesome. You'd certainly get the operating reliability...

Steve

this is just signal, short pulses, a a few ns.... a few tens of us max, period - a few Hz

this would be acceptable

there is problem with voltage of a few tens V. And RF isulation is not enough. But possibly I have take them into account and possibly change conception of signa llayout.

In the (very) old days, tubes were used as amplifiers in undersea cables so I expect their lifetime may be reasonable..

I remember a story about another undersea cable going in after transistors were available. They used tubes because they knew how long they would last but transistors hadn't been around long enough to establish good lifetime data.

Anybody else remember that story?

--
These are my opinions, not necessarily my employer's.  I hate spam.