Wideband noise shaping split LNA architecture
AssigneeMurata Manufacturing Co., Ltd.
InventorsEmre Ayranci, Miles Sanner, Anoop Sheokand, Mengsheng Rui
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Abstract
Split low noise amplifier (LNA) architectures providing an improved tradeoff between the noise figure (NF) and the output-to-output isolation are disclosed. The described LNAs include cascode transistors in two amplification paths and an inductive element including a pair of inductors and a common inductor. The inductance values of the inductors and the common inductor can be selected to obtain an improved tradeoff between the NF and isolation while meeting the output matching conditions.
Claims20
A low noise amplifier (LNA) comprising:
- an input transistor, a first transistor, and a second transistor;
- an inductive element comprising a pair of mutually coupled inductors;
- a first end of the inductive element and drain-terminals of the first and the second transistors being tied together, and a second end of the inductive element being coupled to a bias voltage;
- wherein:
- the LNA is configured to receive an input signal from an input terminal, and to generate a first output signal at a first output terminal, and a second amplified signal at a second output terminal, the input terminal being coupled to the input transistor;
- and
- inductance values of each inductor of the pair of mutually coupled inductors and a degree of mutual coupling of the pair of mutually coupled inductors are selectable to control noise figure and output-to-output isolation values while maintaining a set output matching condition.
A low noise amplifier (LNA) comprising:
- an input transistor, a first transistor, and a second transistor;
- an inductive element comprising:
- a first inductor coupled to a drain terminal of the second transistor;
- a second inductor coupled to a drain terminal of the third transistor, and
- a common inductor tied at a common node together with the first and second inductor,
- wherein:
- the LNA is configured to receive an input signal from an input terminal, and to generate a first output signal at a first output terminal, and a second amplified signal at a second output terminal, the input terminal being coupled to the input transistor;
- and
- inductance values of the first and the second inductor and the choke inductor are selected to meet desired noise figure and output-to-output isolation values while maintaining a set matching condition.
A method of adjusting a noise figure and output-to-output isolation in a low noise split amplifier (LNA), the split LNA comprising:
- an input transistor, a first transistor, and a second transistor, wherein the input transistor and the first transistor form a first amplification path, and the input transistor and the second transistor form a second amplification path distinct from the first amplification path;
- and
- an inductive element comprising a pair of mutually coupled inductors;
- a first end of the inductive element and drain-terminals of the first and the second transistors being tied together,
- the method comprising
- controlling a coupling factor of the pair of mutually coupled inductors;
- and
- adjusting the noise figure and the output-to-output isolation of the LNA while maintaining a set output matching.
Dependencies are inferred from the claim text.