How do you use latched type RF relays?

[tkamiya]

I have LOTS of nice RF relays.  The problem is, they are all latched type and spec sheet prohibits continuously supplying current to the coil.

Say I have two push buttons and give a short pulse to one terminal.  One would assume relay switched to the corresponding port.  But how do you know for sure?  Relay could get stuck, coil can burn out, all kinds of things could happen. 

I know there are latched type relays with separate contact just for this purpose.  That's not what I have.  I have 1 sma port for input, 2 sma ports for output, and 3 DC pins.  Ground, port A enable, and port B enable.  I am thinking of creating a switching matrix.  I could, perhaps pass DC via DC block and coil, and pick up at output the same way, but that's a lot of work with possible degradation of signal.

My tired brain can't come up with any good solution.  I am hoping someone has an answer.
Anyone?

By the way, my use case is to switch between different GPS antenna, so frequency range is about 1.5GHz.  To begin, will have 4 ports out, 1 port in.  That means signal coming in are almost identical and selection will stay for a while.  I need some kind of an indicator.

Taka

[Kalvin]

Use three other RF relays for testing the actual relay. When you switch the actual relay, you will get an interruption anyway, so you could use these three other relays to check what is the state of the contacts of the actual relay. Say you have port 1 for the common path and ports 2 and 3 for different antennas. Now, you place three RF-relays to these three ports, and feed the actual signal through these relays. However, you can use these three relays to switch in a DC-voltage signal which can be used to testing the actual relay contacts. Increasing circuit complexity will also reduce its reliability, but you can at least figure out whether the relays are working ok, including the actual relay you are trying to monitor. I am not sure whether this will degrade the GPS signal too much to be a useful idea, but at least you can get some good use to your RF relays

[ejeffrey]

Those relays are super reliable when driven properly, but if you want you can detect the armature motion by looking at the voltage/current waveform as you drive it.  We have used that technique when driving these type of relays with a marginal drive pulse.

[KrudyZ]

Most latching RF relays have secondary contacts that are used to break the coil current once the relay has switched.
Check out the data sheet for the HP 33311 series of relays.