RF signal strength measurement

[MoZZZie]

signal strength measurement

I want a simple/accurate design/circuit to measure the signal strength recieved from a repeater at a given point(about 1Km from site).

 

[comalco]

RSSI

Why wouldnt you just use any receiver with a RSSI output and just record the RSSI voltage as a reference??

 

[VSWR]

Signal strength in uV, dBm, dBuV, uV/m, dBuV/m or what?

Borrow a calibrated signal generator (with calibrated output power level):

1) Record the signal strength from the repeater on the S-meter of your trcvr.

2) Replace the antenna connection to the trcvr with a short coaxial cable from the signal generator. Increase the signal level from the generator until the same reading as in 1) above is obtained on the S-meter on your trcvr.

3) Now read the power level in dBm or uV on the display on the signal generator. This is the signal strength (in dBm or uV). Accuracy is depending on the VSWR of your trcvr RX input, fading, etc.

4) I you would like to measure signal strength in uV/m or dBuV/m (field strength), the procedure 1) to 3) above is the same. But to convert signal strength reading in dBm or uV to field strength, an additional step is required. This requires knowledge of your receiving antenna gain, receiving radiation pattern and cable loss.

 

[JNovak]

Get calibrated receiver antenna (with known gain) and calibrated power meter with appropriate diode head, otherwise all your attempts will be amateurish and futile. Since you do not mention signal frequency that is all the help you can get. rgz

 

[Gregcooler]

Analog Device have the right chip to do this which Could measure frequency from DC to 2.5GHz.

Good Luck.

 

[scum]

What is the name of this chip ?

 

[WMAN]

AD8313

 

[syncmaster]

weak signal?

For weak signals(less than -60dBm), How to measure?

 

[bumerang]

Digital RF Field Strength Indicator with LED display

Look at this site for RF Field Strength Indicator, It's simple but maybe useful in some case.

http://www.projects.cappels.org/