The BAT18-04 from Infineon Technologies is a RF PIN Diode with Forward Voltage 0.92 to 1.2 V, Forward Current 100 mA, Reverse Voltage 35 V, Reverse Current 0.02 to 0.2 uA, Thermal Resistance 290 K/W. Tags: Flatpack. More details for BAT18-04 can be seen below.