Power amplifier bias protection for depletion mode transistor
AssigneeAlcatel Lucent
InventorsUlrich Seyfried, Dirk Wiegner
Life of this patent
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Abstract
A power amplifier bias protection for a depletion mode transistor is achieved according to the invention with a threshold voltage adaptation connected to the Gate of the depletion mode transistor. That threshold voltage adaptation controls a supply voltage switch for the Drain of the depletion mode transistor such that when the threshold voltage adaptation measures a voltage applied to that Gate outside a tolerable predefined range, then it activates the supply voltage switch to disconnect the Drain DC feed line. The input of the supply voltage switch is connected to the Drain voltage source of the depletion mode transistor and the output of the supply voltage switch is connected to the Drain DC feed line.
Claims10
An amplifier with a depletion mode transistor wherein a threshold voltage adaptation is connected to the Gate of the depletion mode transistor, that threshold voltage adaptation controlling a supply voltage switch for the Drain of the depletion mode transistor such that when the threshold voltage adaptation measures a voltage applied to that Gate outside a tolerable predefined range, then it activates the supply voltage switch to disconnect the Drain DC feed line.
A method for controlling the Gate-voltage to be applied to a depletion mode transistor from an amplifier, the method comprising the following steps:
- Tapping the Gate-voltage to be applied to that depletion mode transistor;
- Using that tapped Gate-voltage for controlling a supply voltage switch for the Drain of the depletion mode transistor;
- Activating that supply voltage switch according to the tapped Gate-voltage such that it switches off the DC Drain supply voltage line when the Gate-voltage is outside a tolerable predefined range;
- Deactivating that supply voltage switch as soon as the tapped Gate-voltage is within the tolerable predefined range.
A terminal for radio telecommunications comprising an amplifier with a depletion mode transistor wherein a threshold voltage adaptation is connected to the Gate of the depletion mode transistor, that threshold voltage adaptation controlling a supply voltage switch for the Drain of the depletion mode transistor such that when the threshold voltage adaptation measures a voltage applied to that Gate outside a tolerable predefined range, then it activates the supply voltage switch to disconnect the Drain DC feed line.
Dependencies are inferred from the claim text.