I wish I could say my knowledge of electronics was at the level where I could design it myself. At least it's better then my spelling(thanks google) Anyway, I've looked at many schematics and settled on the one below. I'm wanting to detect devices anywhere from 1-3GHz and it seems to me that this should be the circuit to get it done. What do you think? Is it what I'm looking for, and do you have any tips for me? Thanks guys, you're always helpful.

Edit:It's been so long since I've been on my post count is down to zero. HAHAHA

 

Unless it relies on some PN junction non-linearity inside the CA3130 to rectify RF, I fail to see how a 15Mhz OpAmp can detect 3 Ghz????

 

No,it won't work,as your CA3130 won't have much gain at 1-3GHz.
Perhaps you need to put a diode detector in front of the IC!

This circuit would possibly work at fairly low frequencies,but I think you have been looking at the wrong websites.

Try looking at some Ham Radio sites.
Here is a good one:http://www.vk2zay.net/

There is also a "sticky"in the Radio and Communications section of this (AAC) site which has a list of RF websites.

 

I don't have the instruments or meters to measure the Ghz frequency, what do you used for this circuit?

The 555 need a negtive trigger from Hi to Lo, but you put a LED into the E, I'm worried it won't active the trigger.