Threshold voltage adjustment using adaptively biased shield plate

An apparatus, comprising:

• a first lateral diffusion field effect transistor (LDFET) having a first threshold voltage and comprising a first gate electrode, a first drain contact, a first source contact, and a first electrically conductive shield plate separated from the first gate electrode and the first source contact by a first interlayer dielectric;
• a control circuit electrically coupled to the first electrically conductive shield plate and configured to apply to the first electrically conductive shield plate a first gate bias voltage being of a first voltage level to set the first threshold voltage of the first LDFET to a first desired threshold voltage, the first gate bias voltage being temporally offset from a control signal applied to the first gate electrode;
• a second LDFET comprising a second threshold voltage and comprising a second gate electrode, a second drain contact, and a second source contact, the second source contact being electrically connected to the first source contact of the first LDFET, wherein the first desired threshold voltage is equal to the second threshold voltage of the second LDFET;
• a third LDFET having a third threshold voltage and comprising a third gate electrode, a third drain contact, a third source contact, and a second electrically conductive shield plate, the third drain contact being electrically connected to the first drain contact of the first LDFET;
• and
• a fourth LDFET having a fourth threshold voltage and comprising a fourth gate electrode, a fourth drain contact, and a fourth source contact, the fourth source contact being electrically connected to the third source contact of the third LDFET, and the fourth drain contact being electrically connected to the second drain contact of the second LDFET.