The disclosure provides an electronic device. The electronic device includes a substrate (110), a transistor (120), and a variable capacitor (130). The transistor is disposed on the substrate. The variable capacitor is disposed on the substrate and adjacent to the transistor. A material of the transistor and a material of the variable capacitor both a include a III-V semiconductor material. The electronic device of an embodiment of the disclosure may simplify manufacturing process, reduce costs, or reduce dimensions.