Cascode amplifier and method for controlling current of cascode amplifier
First Claim
1. A cascode amplifier, comprising:
- an input signal terminal;
an output signal terminal;
a first transistor and a second transistor, wherein each of the first and the second transistors has a gate electrode, a first electrode and a second electrode, the first electrode of the first transistor is coupled to the second electrode of the second transistor, the gate electrode of the first transistor is coupled to the input signal terminal, and the first electrode of the second transistor is coupled to the output signal terminal;
a third transistor and a fourth transistor, wherein each of the third and the fourth transistors has a gate electrode, a first electrode and a second electrode, the first electrode of the third transistor is coupled to the second electrode of the fourth transistor, and the gate electrodes of the third and the fourth transistors are coupled to the gate electrodes of the first and the second transistors, respectively; and
a bias circuit, coupled to the first electrode of the fourth transistor, for biasing a voltage level at the first electrode of the fourth transistor to make the second and the fourth transistors operate in a same region.
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Abstract
A cascode amplifier includes a first transistor, a second transistor, a third transistor, a fourth transistor and a bias circuit. Each of the transistors has a gate electrode, a first electrode and a second electrode, a first electrode of the first transistor is coupled to a second electrode of the second transistor, a first electrode of the third transistor is coupled to a second electrode of the fourth transistor, and gate electrodes of the third and the fourth transistors are coupled to gate electrodes of the first and the second transistors, respectively. The bias circuit is coupled to the first electrode of the fourth transistor, and is used for biasing a voltage level at the first electrode of the fourth transistor to make the second and the fourth transistors operate in a same region.
40 Citations
12 Claims
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1. A cascode amplifier, comprising:
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an input signal terminal; an output signal terminal; a first transistor and a second transistor, wherein each of the first and the second transistors has a gate electrode, a first electrode and a second electrode, the first electrode of the first transistor is coupled to the second electrode of the second transistor, the gate electrode of the first transistor is coupled to the input signal terminal, and the first electrode of the second transistor is coupled to the output signal terminal; a third transistor and a fourth transistor, wherein each of the third and the fourth transistors has a gate electrode, a first electrode and a second electrode, the first electrode of the third transistor is coupled to the second electrode of the fourth transistor, and the gate electrodes of the third and the fourth transistors are coupled to the gate electrodes of the first and the second transistors, respectively; and a bias circuit, coupled to the first electrode of the fourth transistor, for biasing a voltage level at the first electrode of the fourth transistor to make the second and the fourth transistors operate in a same region. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method for controlling a current of a cascode amplifier, comprising:
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providing a first transistor and a second transistor, wherein each of the first and the second transistors has a gate electrode, a first electrode and a second electrode, the first electrode of the first transistor is coupled to the second electrode of the second transistor, the gate electrode of the first transistor is coupled to an input signal terminal, and the first electrode of the second transistor is coupled to an output signal terminal; providing a third transistor and a fourth transistor, wherein each of the third and the fourth transistors has a gate electrode, a first electrode and a second electrode, the first electrode of the third transistor is coupled to the second electrode of the fourth transistor, and the gate electrodes of the third and the fourth transistors are coupled to the gate electrodes of the first and the second transistors, respectively; and biasing a voltage level at the first electrode of the fourth transistor to make the second and the fourth transistors operate in a same region. - View Dependent Claims (8, 9, 10, 11, 12)
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Specification