A GaAs Junction Varactor With a Continuously Tunable Range of 9 : 1 and an $OIP_{3}$ of 57 dBm

In this letter, a junction varactor is presented with a large capacitance tuning range, while providing very high linearity. Such varactors are extremely useful in adaptive RF applications, which directly benefit from passive components with high tuning range and high linearity. Using a preproduction GaAs process technology and third-order intermodulation (
IM

₃
) cancellation techniques, a very linear device is created with a capacitance tuning range as large as 9 : 1 over a control voltage range from 0 to 15 V. Its third-order output intercept point is 57 dBm; the average quality factor is ~ 50, and the breakdown voltage is 28 V. These measured results represent the current state-of-the-art in tuning range, linearity, and quality factor among all existing continuously tunable elements.