Hello-
I am new to RF, so excuse please.
My CDMA 3G phone has a reading in its settings that says it puts out -77 dBm or thereabouts when making or receiving a call.
While idle, it says -82 dBm.
I read similar dBm on another CDMA phone.
These phones operate either in the 800MHz or 1.9Ghz band according to the carrier's dox.
I want to design with an RF detector chip that will detect when this phone is in use and provide a signal strength output. The same chip needs to be able to detect and provide a signal strength output for the Wi-Max band (3.5 GHz).
In one of AD's tutorials I read that the best choice for CDMA and Wi-Max is an RMS detector rather than logarithmic. True?
For lower frequencies I have been using an inductor as the antenna, but have since read that an inductor will not work with GHz digital outputs.
Questions:
What kind of antenna is best to use?
What is the circuitry that connects this antenna?
Can I use one antenna for multiple frequencies?
Is there some documentation to read about this that goes along with the RF chips?
For a chip such as AD8362 which the output is "linear in dB", what does this mean, and do I need another chip to decode?
-Getting a linear voltage output is most desirable simply because it seems the easiest to work with.
Thanks in advance.
