RF Module LNA Layout Using Shared External Inductor
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Solution Overview
Problem
The existing technology of using metal wire inductors in integrated circuits for low-noise amplifiers results in increased circuit size due to the need for larger spaces for inductors, which affects the amplifier's characteristics and requires low-loss inductors, making it challenging to create compact radio-frequency modules with improved performance.
Innovation Solution
A radio-frequency module design that incorporates an integrated circuit with low-noise amplifiers and external inductors, where the external inductor is coupled between the switching circuit and ground, reducing the space required for inductors within the IC and enhancing the Q factor for improved electrical characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If inductors are formed by using metal wire in integrated circuit, then low-noise amplifier characteristics can be achieved, but the size of integrated circuit increases
Solution Approach 1:
The patent moves the inductor from the integrated circuit plane to an external three-dimensional structure. The inductor is positioned outside the IC device and coupled through a switching circuit, effectively utilizing external space rather than consuming valuable IC area. This dimensional transition from 2D integrated circuit layout to 3D external configuration resolves the space constraint while maintaining the necessary inductive function for low-noise amplifier operation.
Solution Approach 2:
The inductor is extracted from the integrated circuit device and placed externally. The IC device includes a switching circuit that couples the amplifier transistor to the external inductor, separating the inductive function from the integrated circuit fabrication. This extraction eliminates the need for large metal wire inductors within the IC, significantly reducing the integrated circuit area while preserving the low-noise amplifier characteristics that depend on the inductor.
2Adaptability or versatility
If multiple low-noise amplifiers are integrated together, then functionality is improved, but the size of integrated circuit further increases due to spaces for inductors
Solution Approach 1:
The external inductor serves multiple low-noise amplifiers simultaneously through the switching circuit. Instead of requiring separate inductors for each amplifier within the IC, a single external inductor can be shared among multiple amplifier transistors by selectively coupling them through the switching circuit. This multi-functional approach enables multiple low-noise amplifiers to be integrated without proportionally increasing the IC area, as the inductive resource is universally utilized across multiple functional units.
Solution Approach 2:
By moving the inductor to an external position and using a switching circuit for selective coupling, the patent enables multiple amplifiers to share the same external inductive resource. This external configuration with switching control allows one inductor to serve multiple amplifiers, resolving the contradiction between having multiple amplifiers for improved functionality and maintaining compact IC size.
3Reliability
If inductor is coupled to source or emitter of amplifier transistor, then low-noise amplifier characteristics are achieved, but low-loss inductor is required which increases complexity
Solution Approach 1:
The inductor is extracted from the integrated circuit and placed externally, where it can be implemented as a discrete component with optimized low-loss characteristics. External inductors can be constructed with higher quality factors using standard inductor technologies without the area and loss constraints of integrated metal wire inductors. This extraction simplifies the overall design by allowing the use of specialized low-loss inductor components rather than requiring complex integrated inductor structures.
Solution Approach 2:
The switching circuit acts as an intermediary between the amplifier transistor and the external inductor, enabling the coupling necessary for low-noise amplifier characteristics. This intermediary switching mechanism allows the external inductor to be selectively connected to the amplifier source or emitter, achieving the desired amplifier performance without requiring the inductor to be physically integrated with the transistor. The switching circuit mediates the interaction, simplifying both the inductor design and the amplifier implementation.
Data Source
AI summary
A radio-frequency module includes an integrated circuit (IC) device and an external inductor provided outside the IC device. The IC device includes a plurality of low-noise amplifiers, one or more inductors, and a switching circuit. The plurality of low-noise amplifiers includes a plurality of transistors in one to one correspondence. The one or more inductors are coupled to one or more of the plurality of transistors. Each inductor is coupled to the emitter or source of a corresponding one of the plurality of transistors. The switching circuit is coupled between the emitter or source of each of the plurality of transistors and the external inductor. The external inductor is coupled between the switching circuit and ground in series with each of the one or more inductors via the switching circuit.