Differential Inductor Power Splitter for Low-Loss RF Circuits
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Solution Overview
Problem
Radio-frequency circuits with amplifiers and power splitters face significant signal power loss and large size due to the use of resistors for signal splitting, which can be mitigated by replacing resistors with differential inductors and resistor elements in the power splitter, allowing for miniaturization and reduced footprint.
Innovation Solution
The proposed radio-frequency circuit incorporates a differential inductor and a resistor element in the power splitter, where the inductor lines are wound in opposite directions with the same coil axis, eliminating the need for resistors and enabling impedance matching between the amplifier and power splitter without additional matching circuits, thus minimizing signal power loss and reducing circuit size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If resistors are used in the power splitter, then the circuit structure is simple, but signal power loss increases significantly
Solution Approach 1:
The patent changes the fundamental parameter of the power splitter from using resistive elements to using reactive elements (inductors and capacitors). This transformation allows the circuit to operate based on impedance matching and reactive power division rather than resistive power dissipation, thereby reducing signal power loss while maintaining circuit functionality.
Solution Approach 2:
The patent replaces the resistive power splitting mechanism with a reactive power splitting mechanism using inductors and capacitors. This substitution eliminates the inherent power loss associated with resistors while achieving the same power division function through reactive impedance manipulation.
2Loss of energy
If inductors are used in the power splitter circuit, then signal power loss is reduced, but the circuit footprint increases
Solution Approach 1:
The patent merges the power splitter function with the impedance matching circuit by using shared inductors and capacitors. The same reactive elements serve dual purposes: dividing the output power while simultaneously providing impedance transformation and matching between the amplifier and the power splitter. This integration eliminates the need for separate matching circuits, thereby reducing the overall footprint.
Solution Approach 2:
The inductors and capacitors in the power splitter are designed to perform multiple functions simultaneously: power division, impedance matching, and frequency selectivity. This multi-functionality reduces the total number of components required, thereby minimizing the circuit footprint while maintaining low signal power loss.
3Reliability
If additional impedance matching circuits are added, then impedance matching is improved, but the circuit size increases
Solution Approach 1:
The patent integrates the impedance matching function into the power splitter structure itself. The inductors and capacitors used for power division are configured to also provide the necessary impedance transformation. This merging of functions eliminates the need for separate matching circuits, achieving good impedance matching without increasing circuit size.
Solution Approach 2:
The reactive elements in the power splitter are designed with dual functionality: power splitting and impedance matching. By carefully selecting the values and configurations of these elements, the circuit achieves both power division and impedance matching simultaneously, avoiding the need for additional dedicated matching components.
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
This configuration reduces signal power loss from 6 dB to 3 dB and allows for a smaller footprint, enabling the integration of the amplifier, matching circuit, and power splitter into a semiconductor integrated circuit, thereby achieving a compact and efficient radio-frequency circuit.
Implementation Method 1
The differential inductor includes an input node, a first line, and the second line. The input node is connected to the matching circuit. The first and second lines are respectively wound into coil form and connected to the input node. The first and second lines are wound in opposite directions and have the same coil axis.
Data Source
AI summary
A radio-frequency circuit includes: an amplifier; a matching circuit connected to an output side of the amplifier; and a power splitter connected to an output side of the matching circuit. The power splitter includes a differential inductor and a resistor element. The differential inductor includes an input node (ni), a first line, and a second line. The input node (ni) is connected to the matching circuit. The first line and the second line are respectively wound into coil form and connected to the input node (ni). The resistor element forms a connection between a node (n1) on an output side of the first line and a node (n2) on an output side of the second line. The first line and the second line are wound in opposite directions and have the same coil axis.