According to the datasheets, the peak forward voltage is 0.975.The maximum continuous forward current that this device consumes at any given time is about 2.5.A DC reverse voltage less than 110 must be used for operation.
GRP-A-DATA-JANTX1N5804 Features
the forward peak voltage is 0.975
GRP-A-DATA-JANTX1N5804 Applications
There are a lot of Microsemi GRP-A-DATA-JANTX1N5804 applications of RF diodes.