These switches are a combination of a depletion type Field-Effect Transistor (FET) and a
band-switching diode. The BF1118, BF1118R, BF1118W and BF1118WR are
encapsulated in the SOT143B, SOT143R, SOT343N and SOT343R respectively. The low
loss and high isolation capabilities of these devices provide excellent RF switching
functions. The gate of the MOSFET can be isolated from ground with the diode, resulting
in low losses. Integrated diodes between gate and source and between gate and drain
protect against excessive input voltage surges.