I have tablet phone samsung galaxy tab... when I check the signal strength, it shows -82 dbm... I thought it is produced by the Signal PA (Power Amplifier) on the PCB... According to what I know, the signal from the handphone is so weak to reach the nearest terrestrial station on the earth, so it is amplified by the Power Amplifier... But when it show -82dbm, it means deamplified... Any correction for this? What is the purpose making it with minus sign?