the varactor has spoil

I think you you are asking about varactor diode. varactor means variable capacitor. varactor diode is a p-n junction diode which provide a capacitance across it subjected to applied forward and reverse bias.

means it provide variable capacitance which depends on the applied reverse voltage(mostly varactor diode works on reverse voltage).They are also known as varicap

YES

invented by Arthur Uhlir and A. Bakanowski

varactor diode is a correct answer