Active Device Technologies
Mike Golio · 2000
A varactor is a nonlinear reactive device used for harmonic generation, parametric amplification, mixing, detection, and voltage-variable tuning. However, present applications of varactors are mostly for harmonic generation at millimeter and submillimeter wave frequencies, and as tuning elements in various microwave applications. Varactors normally exhibit a voltage-dependent capacitance and can be fabricated from a variety of semiconductor materials.