8-Shaped Inductor Layout for VCO-PA Coupling Suppression
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Solution Overview
Problem
In direct-up transmitters, the voltage controlled oscillator (VCO) is often pulled by the power amplifier due to coupling between inductor components, leading to deteriorated communication quality, and existing solutions require additional elements or complex calibration to address this issue.
Innovation Solution
An inductor device comprising an 8-shaped inductor and a ring-type wire, where the ring-type wire is disposed around the 8-shaped inductor, with specific terminal configurations to form currents with opposite directions, effectively reducing coupling between the VCO and power amplifier.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the frequency of the voltage controlled oscillator is configured at non-integer multiple of the harmonic frequencies of the power amplifier to avoid coupling, then the coupling between VCO and power amplifier is reduced, but additional elements/components are required which occupy space and may cause other interferences
Solution Approach 1:
The patent utilizes the harmful coupling effect between VCO and power amplifier by designing the 8-shaped inductor with a specific winding direction such that the magnetic field from the power amplifier's inductor induces a current in the VCO's inductor that opposes the original oscillation. This converts the harmful coupling into a beneficial negative feedback mechanism that stabilizes the VCO frequency without requiring additional components.
Solution Approach 2:
The patent changes the physical parameter of the inductor winding direction in the 8-shaped structure. By controlling the winding direction of one of the inductors in the 8-shaped configuration, the patent creates a specific magnetic coupling polarity that generates the desired opposing current, thereby adjusting the system's electromagnetic parameters to achieve frequency stability.
2Object-affected harmful factors
If an algorithm is used to perform calibration to resolve the coupling issue, then the coupling between VCO and power amplifier can be compensated, but the algorithm is difficult to implement because there are numerous paths in which the voltage controlled oscillator may be affected
Solution Approach 1:
The patent extracts the complex calibration algorithm requirement by implementing a passive structural solution instead. The 8-shaped inductor configuration with controlled winding direction creates an automatic magnetic feedback mechanism that eliminates the need for active calibration algorithms, thereby removing the computational complexity while still addressing the coupling issue.
Solution Approach 2:
The patent implements a self-regulating system where the 8-shaped inductor structure automatically compensates for coupling effects through its inherent magnetic field interactions. The winding direction configuration ensures that the induced current automatically opposes frequency deviations, creating a self-correcting mechanism without external control algorithms.
3Productivity
If the voltage controlled oscillator frequency is set at the same frequency as the even harmonics of the power amplifier, then the device operates efficiently, but the voltage controlled oscillator is pulled by the power amplifier leading to deteriorated communication quality
Solution Approach 1:
The patent maintains efficient operation at harmonic frequencies while converting the harmful pulling effect into a beneficial stabilizing mechanism. The 8-shaped inductor's specific winding direction creates a magnetic feedback that counteracts frequency pulling, allowing the system to operate at efficient harmonic frequencies without sacrificing communication quality.
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 allows for reduced coupling between the voltage controlled oscillator and the power amplifier, improving communication quality without the need for additional space or complex calibration, as demonstrated by reduced phase noise in experimental data.
Implementation Method 1
an interference signal forming currents respectively in the 8-shaped inductor and the ring-type wire when the interference signal is fed from the center-tapped terminal, wherein the current in the 8-shaped inductor has an opposite direction to the current in the ring-type wire
Data Source
AI summary
An inductor device includes an 8-shaped inductor and a ring-type wire. The ring-type wire is disposed around an outer side of the 8-shaped inductor. The 8-shaped inductor includes an input terminal and a center-tapped terminal. The input terminal of the 8-shaped inductor is located on a first side of the inductor device, and the center-tapped terminal is located on a second side of the inductor device. The ring-type wire includes an input terminal and a ground terminal. The input terminal of the ring-type wire is located on the first side of the inductor device, and the ground terminal is located on the second side of the inductor device. The input terminal of the ring-type wire is coupled to the input terminal of the 8-shaped inductor.