Superimposed Multimode Antenna with Parasitic Filtering
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Solution Overview
Problem
In mobile wireless communication systems, the de-tuning of antennas due to multiple use cases leads to impedance variations, reducing power transfer and communication range, and increasing filtering complexity, which results in reduced data rates and communication range.
Innovation Solution
A multimode antenna with symmetric and asymmetric frequency roll-off is developed, utilizing an adaptive transceiver and active modal antenna systems with parasitic elements and tunable filters to optimize signal levels and reject unwanted frequencies, thereby enhancing filtering performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If more filtering is added to handle multiple frequency bands, then filtering performance is improved, but system losses increase and communication range is reduced
Solution Approach 1:
The patent combines the filtering function with the antenna structure itself by introducing parasitic elements that create frequency-selective interference patterns. This merges the antenna radiation function with the filter rejection function into a single integrated structure, eliminating the need for separate filtering components and reducing overall system losses while maintaining filtering performance.
Solution Approach 2:
The antenna structure is designed to perform multiple functions simultaneously: radiation of electromagnetic signals and frequency-selective filtering. The parasitic elements enable the same antenna structure to both transmit/receive signals and reject unwanted frequencies, reducing the need for additional dedicated filtering components that would add to system losses.
2Ease of manufacture
If passive antenna with fixed impedance matching is used, then manufacturing simplicity is maintained, but adaptability to different use cases is reduced
Solution Approach 1:
The patent introduces active elements and control circuitry that enable dynamic adjustment of the antenna's impedance matching and radiation characteristics. This allows the antenna to adapt its electrical properties in real-time based on different use cases (hand-held, head-mounted, surface placement) while maintaining a relatively simple physical structure that doesn't complicate manufacturing.
Solution Approach 2:
The antenna system changes its electrical parameters (impedance, radiation pattern, resonant frequency) dynamically based on detected use conditions. By adjusting these parameters rather than changing the physical structure, the system achieves high adaptability across different use cases while maintaining manufacturing simplicity.
3Device complexity
If antenna de-tuning is allowed to occur, then device complexity is reduced, but power transfer and communication range are reduced
Solution Approach 1:
The patent incorporates feedback mechanisms that monitor the antenna's impedance and performance characteristics in real-time. Based on this feedback, the system automatically adjusts matching network parameters or active element states to maintain optimal power transfer. This closed-loop control prevents de-tuning losses without requiring complex manual intervention or overly complicated fixed structures.
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 improves communication range and data rate by dynamically adjusting the antenna's radiation pattern and frequency response, reducing insertion loss and enhancing out-of-band rejection, thus addressing the challenges of impedance matching and filtering complexity.
Implementation Method 1
an antenna system includes an antenna element and one or more parasitic elements... The frequency response of the antenna element is adjusted to the desired frequency of operation
Implementation Method 2
one or more parasitic elements... positioned around the antenna element... The frequency response of the antenna element is adjusted to the desired frequency of operation
Data Source
AI summary
In a typical system a combination of filters (BAW, SAW, etc) and an antenna are configured to achieve frequency filtering effect and efficient transmission and reception of communication signals. Wireless communication systems require specific bandwidth and out-of-band rejection; typically this metric is characterized in frequency roll-off in units of dB/MHz. This number is distributed between the antenna and filter, with the antenna contributing little to date to the filtering effect. Loss and cost penalties are incurred when multi-mode systems are designed which require additional rejection from the filter elements. Described here is a method of designing antennas to reduce the amount of rejection and complexity from the filter system. A superposition of a symmetrical frequency response from the antenna structure coupled with a non-symmetrical frequency response from a counterpoise structure generates increased rejection of out-of-band components.