Time-Variant Antenna Using Switched Capacitor Array
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Solution Overview
Problem
Existing antennas face challenges with size, cost, and complexity due to the need for varactors and waveform generators, which also introduce non-linearity and intermodulation issues in transceivers.
Innovation Solution
A time-variant antenna system utilizing a switched capacitor array on a silicon substrate replaces varactors and waveform generators, providing high linearity, reduced size, and lower cost by using a switched capacitor logic unit with control logic and parallel capacitors, which can be digitally configured to adjust capacitance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a varactor and waveform generator are used to adjust antenna resonant frequencies, then the antenna becomes more flexible in operation, but the cost, size, and complexity of the system increase
Solution Approach 1:
The patent combines the waveform generator and varactor into an integrated switched capacitor array module that is directly coupled to the antenna element, eliminating the need for separate components and reducing system complexity while maintaining frequency adjustment capability
Solution Approach 2:
The switched capacitor array serves multiple functions: it acts as both the tuning mechanism and the interface between the digital control logic and the antenna, allowing a single component to perform what previously required multiple separate devices
2Adaptability or versatility
If a varactor is used to adjust antenna properties, then the resonant frequencies and bandwidth can be changed, but non-linear intermodulation is generated in the transceiver
Solution Approach 1:
The patent replaces the non-linear varactor device with a linear switched capacitor array controlled by digital logic, substituting the mechanical/electrical non-linear tuning mechanism with a digital control system that eliminates intermodulation distortion while maintaining frequency adjustment capability
3Ease of operation
If an off-the-shelf variable capacitor is used, then the antenna can be tuned, but the non-linear device generates undesired intermodulation
Solution Approach 1:
The patent changes the fundamental operating parameter of the tuning mechanism from continuous voltage-controlled capacitance variation (non-linear) to discrete digital-controlled capacitor switching (linear), fundamentally altering how the antenna is tuned while eliminating the harmful non-linear effects
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 achieves improved performance with reduced size and cost, eliminates intermodulation issues, and allows for self-calibration, making it suitable for integrated wireless communications and multi-antenna systems.
Implementation Method 1
A time-variant antenna system utilizes a switched capacitor array on a silicon substrate replaces varactors and waveform generators, providing high linearity, reduced size, and lower cost by using a switched capacitor logic unit with control logic and parallel capacitors, which can be digitally configured to adjust capacitance.
Implementation Method 2
Antennas are used in a variety of devices to transmit electrical currents, converted into radio waves, to a remote device that also has an antenna.
Data Source
AI summary
A time-variant antenna is disclosed that uses a switched capacitor array in silicon to improve the performance and integration options of the time-variant antenna. Parasitic effects of the interface between the on-board antenna and on-silicon switched capacitor array are considered and the antenna is tuned to compensate for these effects. The switched capacitor array provides high linearity, lower cost, and reduced size, relative to prior art antenna implementations.