This paper presents the design of a driver amplifier (DA) for a cordless mouse application, operating at the 2.4GHz ISM unlicensed band. The DA is a single-ended topology, and is composed of two stages: the first stage is a cascode amplifier to provide high gain and good input-output isolation, while the output stage is a simple common source amplifier that adopts a novel current reuse scheme to reduce the DC bias current by half. The DA implemented in a 0.18µm CMOS process has a 16dB gain at 2.4GHz, and it can drive a 3dBm to the antenna with an output stage drain efficiency of 31% and a power-added efficiency (PAE) of 20% while drawing 4.5mA from a 1.8V supply.