Question: I've been looking at various RF power detectors for a project I'm working on, but I don't quite understand what the manufacturers mean by "dB range".

For example, the [LT5534](http://cds.linear.com/docs/en/datasheet/5534fc.pdf) Log RF Power Detector has a frequency range of 50 MHz - 3 GHz; the minimum it can detect is -63dB and the maximum is 2 dB. What does that mean?

Answer: 
-63 dBm is roughly equivalent to 1 nano Watts
while 
-2 dBm is equivalent to 0.6 milliwatts

All it says is that the device has 61dB (-63dbm minus -2dBm) dynamic range (power range where it will provide linear and correct measurements) and it overloads once you feed it above -2dBm or 0.6 milliwatts.

here is the transfer curve

![enter image description here](https://i.stack.imgur.com/Sto7P.jpg)

Your Vout will register 0.2V if you feed it -60dBm signal bet (50MHz to 3GHz)
while Vout will register near 2.4V(maybe 2.39xxxxxV) if you feed it -2dBm signal bet (50MHz to 3GHz)
It is actually -63dBm and 2dB , depending on the frequency. It means the range of RF signal to which there is a linearly related output voltage. This detector is equivalent to an anti logarithmic function.