In the datasheets, 1.7 is stated as the peak forward voltage.A continuous forward current of 1 is the maximum consumption of this device.RF diode is necessary to operate the device at a DC reverse voltage below 600.
SFT18G R0 Features
the forward peak voltage is 1.7
SFT18G R0 Applications
There are a lot of Taiwan Semiconductor SFT18G R0 applications of RF diodes.