Dual Coupler 取直
目的 :
Dual Coupler 分
FW 順向 Power
RV 反向 Power
開路時
目標 FW = RV
實際做法 :
讀 FW & RV
RV=讀 RV + Offset
exp.
-5@1GHz FW
-4@ GHz RV
offset = ( FW-RV) = -1
exp 2
-10@2GHz ..... FW
-12@2GHz ----RF
Offset = -10-(-12) = 2dB
RV = 讀 RF+ Offset = 12+2 = -10dB