Power Splitter and LNA Matching for Smaller RF Distribution Circuits
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Solution Overview
Problem
Wilkinson splitters require multiple ¼ wavelength transmission lines, making it difficult to reduce the circuit area of wireless signal distribution circuits.
Innovation Solution
A distribution circuit with a low noise amplifier and a power splitter that includes input and output matching circuits, utilizing resistive elements and complex conjugate relationships to reduce impedance conversion ratio and circuit area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a Wilkinson splitter is used to distribute wireless signals, then the distribution function is achieved, but the circuit area increases due to multiple ¼ wavelength transmission lines
Solution Approach 1:
The patent changes the impedance parameters from conventional 50Ω to optimized values (30Ω for series resistors, 70Ω for shunt resistors) to reduce the impedance conversion ratio required from the LNAs. This parameter optimization allows the use of shorter transmission lines and smaller matching circuits, directly reducing the overall circuit area while maintaining proper signal distribution functionality
Solution Approach 2:
The power splitter is divided into independent functional blocks: series resistors, shunt resistors, and output matching circuits. This segmentation allows each component to be optimized separately for minimal area, rather than using a monolithic Wilkinson design that requires fixed ¼ wavelength lines. The modular approach enables compact layout without compromising the distribution function
2Area of stationary object
If the impedance conversion ratio of output matching circuits is reduced, then the circuit area decreases, but the impedance matching becomes more difficult to achieve
Solution Approach 1:
The patent optimizes the resistor values (30Ω series, 70Ω shunt) to create a more favorable impedance transformation ratio. This parameter change makes the impedance matching task easier and allows the use of smaller, more compact matching circuits with fewer elements, directly reducing area while improving manufacturability
Solution Approach 2:
The series and shunt resistors act as intermediary elements that prepare the impedance before it reaches the output matching circuits. By pre-conditioning the impedance through these resistor networks, the matching circuits face a less demanding transformation task, enabling smaller circuit area while maintaining accurate impedance matching
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution achieves reduced circuit area and cost while maintaining high gain, wide bandwidth, and low loss, with improved inter-output terminal isolation and output return loss.
Implementation Method 1
an input matching circuit that converts an input impedance of a downstream circuit
Implementation Method 2
a first output matching circuit that converts a first load impedance into a first impedance related to a load impedance ZL of the low noise amplifier, and a second output matching circuit that converts a second load impedance into a second impedance related to the ZL
Implementation Method 3
the ZL may be approximately in a complex conjugate relationship with an output impedance Zao of the low noise amplifier
Data Source
AI summary
Reduced circuit area in a reception device that distributes wireless signals is disclosed. In one example, a low noise amplifier includes an input matching circuit that converts an input impedance of a downstream circuit, and an amplifier circuit that amplifies a wireless signal received from the input matching circuit. A power splitter includes a first output matching circuit that converts a first load impedance into a first impedance related to a load impedance ZL of the low noise amplifier, and a second output matching circuit that converts a second load impedance into a second impedance related to the ZL.