Step-Symmetric Inductor Layout for VCO Pulling and Spur Reduction
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Solution Overview
Problem
Conventional transceivers face challenges such as high power consumption, generation of spurs, and voltage-controlled oscillator (VCO) and/or local oscillator (LO) pulling, which are not effectively addressed in existing wireless communication systems.
Innovation Solution
The implementation of a transceiver using a step-symmetric and dual-core structure inductive element, specifically in a zero-intermediate frequency (IF) and half-LO architecture, which includes a frequency doubler circuit with a step-symmetric inductive element to reduce magnetic emissions and power consumption, and cancel magnetic fields.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional transceiver architecture is used, then basic wireless communication functions are achieved, but power consumption is high and magnetic emissions cause spurs and VCO/LO pulling
Solution Approach 1:
The inductive element is segmented into multiple segments (first inductive segment, second inductive segment, third inductive segment) arranged in a step-symmetric pattern. Each segment carries current in opposite directions, creating opposing magnetic fields that cancel each other out. This segmentation allows the frequency synthesizer to generate required magnetic fields for frequency multiplication while canceling harmful magnetic emissions that cause spurs and VCO/LO pulling, thereby reducing power consumption without compromising frequency stability.
Solution Approach 2:
The patent employs a step-symmetric inductive element structure where segments are positioned asymmetrically relative to each other in terms of spatial arrangement but symmetric in terms of magnetic field cancellation. The first, second, and third inductive segments are configured with specific geometric relationships that create asymmetric current paths, resulting in magnetic fields that oppose and cancel each other. This asymmetric configuration enables effective magnetic field cancellation while maintaining the necessary inductive properties for frequency synthesis.
2Object-generated harmful factors
If conventional frequency synthesizer design is used, then frequency generation is achieved, but magnetic emissions generate spurs and cause VCO/LO pulling
Solution Approach 1:
The patent converts the harmful magnetic emissions into a beneficial effect by arranging inductive segments to generate opposing magnetic fields. The magnetic fields that would normally cause spurs and VCO/LO pulling are instead configured to cancel each other constructively. The first inductive segment generates a magnetic field in one direction, while the second and third segments generate opposing fields that neutralize the harmful emissions. This transforms what would be harmful radiative losses into a beneficial cancellation mechanism, reducing both magnetic emissions and associated power consumption.
3Object-affected harmful factors
If step-symmetric inductive element is implemented, then magnetic field cancellation is achieved, but device complexity increases
Solution Approach 1:
The patent merges multiple inductive segments (first, second, and third inductive segments) into a single integrated inductive element structure. Rather than using separate inductors that would require multiple components and connections, the segments are combined into one unified element with a step-symmetric configuration. This merging approach achieves magnetic field cancellation through the internal geometry and current distribution of the single element, reducing the overall device complexity compared to using multiple discrete inductors while still achieving the desired noise reduction.
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 approach reduces noise and power consumption, effectively addressing the issues of spurs and VCO/LO pulling, while enhancing the stability and efficiency of the transceiver's frequency synthesizer.
Implementation Method 1
the frequency adjustment circuit comprising a step-symmetric inductive element... reduces noise and power consumption, effectively addressing the issues of spurs and VCO/LO pulling... cancel magnetic fields
Data Source
AI summary
Certain aspects of the present disclosure provide techniques and apparatus for generating oscillating signals and for wireless communication, such as a frequency synthesizer architecture using a step-symmetric inductor. An example frequency synthesizer generally includes an oscillator and a frequency adjustment circuit, an output of the oscillator being coupled to an input of the frequency adjustment circuit, the frequency adjustment circuit comprising a step-symmetric inductive element. An example transceiver generally includes the frequency synthesizer described herein, as well as a mixer having a local-oscillator (LO) input coupled to an output of the frequency adjustment circuit; and an amplifier coupled to the mixer.