The characteristics of GaAs/InGaP/GaAs camel-gate field-effect transistor (CAMFET) with various channel structures including the single-, double-, and triple-step doped channel are studied. A theoretical model is used to analyze the device performances with different structures. Experimentally, a triple-step doped channel GaAs/InGaP/GaAs CAMFET has been fabricated successfully and demonstrated. From the theoretical analysis and experimental results, the gate turn-on and breakdown voltages could be enhanced by using the large band gap InGaP layer and triple-step doped channel structure. Furthermore, the good transistor characteristics are observed. Hence the studied device shows a good potential for the practice circuit applications.