Tunable Circulator Isolation for Wireless IMD Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Small wireless communication devices face challenges in achieving sufficient antenna isolation due to size constraints and high intermodulation distortion (IMD) issues, which existing miniature circulators fail to address effectively.
Innovation Solution
The implementation of a tunable circulator with a three-port configuration and a coupled tuning network, allowing for static or dynamic tuning to enhance isolation between antennas, effectively reducing IMD products by optimizing the Smith chart synthesis and using RF switches and reactors for enhanced tuning range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a large, tuned and shielded circulator is used to increase antenna isolation, then isolation between antennas is improved, but device size and cost increase
Solution Approach 1:
The patent applies parameter changes by tuning the circulator's electrical characteristics using variable capacitors and inductors to optimize isolation performance. By adjusting capacitance and inductance values, the circulator achieves enhanced isolation without requiring a larger physical size, thus resolving the contradiction between isolation performance and device size.
Solution Approach 2:
The patent introduces a tuning network as an intermediary component between the circulator and the antennas. This tuning network, comprising variable capacitors and inductors, mediates the interaction between the circulator and antennas to achieve optimal isolation performance while maintaining a compact device size.
2Reliability
If a large, tuned and shielded circulator is used to increase antenna isolation, then isolation between antennas is improved, but device cost increases
Solution Approach 1:
The patent uses parameter changes through electronically tunable capacitors and inductors to achieve optimal isolation performance. This approach eliminates the need for expensive large-scale shielded circulators, as the tuning network can be integrated into a compact, cost-effective design while maintaining high isolation levels.
Solution Approach 2:
The patent replaces expensive, large-scale shielded circulators with a combination of inexpensive variable capacitors, inductors, and a standard circulator. This substitution achieves the same isolation performance at a lower cost, making the solution economically viable for handheld devices.
3Volume of moving object
If miniature circulators are used to reduce device size, then device size is reduced, but isolation performance and power handling capability deteriorate
Solution Approach 1:
The patent compensates for the limited performance of miniature circulators by introducing a tuning network with variable capacitors and inductors. By dynamically adjusting the electrical parameters of the tuning network, the system achieves enhanced isolation performance and improved power handling capability while maintaining the compact size benefits of miniature circulators.
Solution Approach 2:
The patent makes the circulator system dynamic by incorporating electronically controllable capacitors and inductors in the tuning network. This allows real-time adjustment of isolation characteristics and power handling capabilities, enabling the miniature circulator to adapt to different operating conditions and achieve performance levels previously only attainable with larger devices.
4Volume of moving object
If antennas are placed closer together to reduce package size, then package size is reduced, but intermodulation distortion increases
Solution Approach 1:
The patent introduces a circulator with tuning network as an intermediary component between the closely spaced antennas. This intermediary actively manages the electromagnetic interactions between antennas, canceling out intermodulation distortion products while allowing the antennas to be positioned closer together for reduced package size.
Solution Approach 2:
The patent applies preliminary anti-action by using the circulator's isolation capability to prevent intermodulation distortion from occurring in the first place. The tuning network is configured to create opposing electromagnetic fields that cancel out the harmful intermodulation products generated by close antenna spacing, thereby preventing rather than correcting the distortion.
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 solution provides enhanced isolation exceeding 20 dB, allowing for closer antenna placement and reduced package size while maintaining full power levels, significantly improving IMD performance in mobile handheld devices.
Implementation Method 1
a first circulator coupled between a first communications arrangement and a first antenna and a second circulator coupled between a second communications arrangement and a second antenna
Implementation Method 2
a first tuning network coupled to a port of the first circulator and a second tuning network coupled to a port of the second circulator
Data Source
AI summary
A mobile wireless communication device includes a circulators coupled between a respective communications arrangement and their antennas. Each circulator includes a coupled tuning network, wherein the tuning networks are operable to tune their circulators for maximum isolation from cross coupling between the power amplifiers within an operating frequency band of the respective communications arrangement.