Low noise amplifier and receiver using same in wireless communication system
The present disclosure relates to a 5G communication system or a 6G communication system for supporting higher data rates beyond a 4G communication system such as long term evolution (LTE). A low noise amplifier (LNA) in a wireless communication system according to an embodiment of the disclosure includes a first transistor and a first feedback transformer in which a gate of the first transistor is connected to a primary coil of the first feedback transformer and a source of the first transistor is connected to a secondary coil of the first feedback transformer. The first feedback transformer is configured to implement positive feedback to maintain an in-phase signal at the gate of the first transistor and the source of the first transistor.
1 . A low-noise amplifier (LNA) in a wireless communication system, the LNA comprising:
a first transistor; and
a first feedback transformer in which a gate of the first transistor is connected to a primary coil of the first feedback transformer and a source of the first transistor is connected to a secondary coil of the first feedback transformer,
wherein the first feedback transformer implements positive feedback to maintain an in-phase signal at the gate of the first transistor and the source of the first transistor.
2 . The LNA of claim 1 , wherein a coupling coefficient of the first feedback transformer is determined such that a k-factor is 1 or greater.
3 . The LNA of claim 1 , further comprising:
a second transistor of which a drain is connected to the gate of the first transistor; and
a second feedback transformer in which a gate of the second transistor is connected to a primary coil of the second feedback transformer and a source of the second transistor is connected to a secondary coil of the second feedback transformer.
4 . The LNA of claim 3 , wherein the second feedback transformer is configured to implement negative feedback that maintains an opposite phase signal at the gate of the second transistor and the source of the second transistor.
5 . The LNA of claim 3 , wherein the first feedback transformer and the second feedback transformer are common source amplifiers.
6 . The LNA of claim 3 , wherein the first feedback transformer or the second feedback transformer is implemented as a cascade amplifier structure.
7 . The LNA of claim 3 , wherein the first feedback transformer is configured to implement, by a control signal, positive feedback to maintain an in-phase signal at the gate of the first transistor and the source of the first transistor, or negative feedback to maintain an opposite-phase signal.
8 . The LNA of claim 1 , wherein a phase of a signal coupled by the first feedback transformer and a phase of a signal implemented by the secondary coil are opposite to each other.
9 . The LNA of claim 1 , further comprising:
a second transistor of which a drain is connected to the gate of the first transistor; and
a first inductor connected to a source of the second transistor and a second inductor connected to a gate of the second transistor.
10 . A receiver configured to receive a radio frequency (RF) signal in a wireless communication system, comprising:
a low-noise amplifier (LNA); and
a signal processor configured to apply the RF signal to the LNA,
wherein the LNA comprises a first transistor and a first feedback transformer in which a gate of the first transistor is connected to a primary coil of the first feedback transformer and a source of the first transistor is connected to a secondary coil of the first feedback transformer, and
wherein the RF signal is applied to the primary coil and then transmitted to the secondary coil in the same phase.
11 . The receiver of claim 10 , wherein a coupling coefficient of the first feedback transformer is determined such that a k-factor is 1 or greater.
12 . The receiver of claim 10 , wherein the LNA further comprises:
a second transistor of which a drain is connected to the gate of the first transistor; and
a second feedback transformer in which a gate of the second transistor is connected to a primary coil of the second feedback transformer and a source of the second transistor is connected to a secondary coil of the second feedback transformer.
13 . The receiver of claim 12 , wherein the second feedback transformer is configured to implement negative feedback that maintains an opposite phase signal at the gate of the second transistor and the source of the second transistor.
14 . The receiver of claim 12 , wherein, in the LNA, the first feedback transformer and the second feedback transformer are common source amplifiers.
15 . The receiver of claim 12 , wherein the first feedback transformer or the second feedback transformer is implemented as a cascade amplifier structure.
16 . The receiver of claim 12 , further comprising:
a control signal processor,
wherein the control signal processor is the first feedback transformer, and is configured to transmit a control signal to implement positive feedback to maintain an in-phase signal at the gate of the first transistor and the source of the first transistor, or to implement negative feedback to maintain an opposite-phase signal.
17 . The receiver of claim 10 , wherein a phase of a signal coupled by the first feedback transformer and a phase of a signal implemented by the secondary coil are opposite to each other.
18 . The receiver of claim 10 , wherein the LNA further comprises:
a second transistor of which a drain is connected to the gate of the first transistor; and
a first inductor connected to a source of the second transistor and a second inductor connected to a gate of the second transistor.