Retroreflective Antenna With Passive Notch Filtering for Radar ID
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Solution Overview
Problem
Existing Van Atta array antennas face challenges in distinguishing between reflections from reflectors with and without retroreflection functionality, leading to increased manufacturing costs and weight due to the need for power supplies to superimpose information on retroreflected radio waves.
Innovation Solution
A retroreflective antenna design incorporating a passive notch filter in transmission lines to attenuate specific frequencies, allowing information to be superimposed on retroreflected radio waves without requiring a power supply, using a configuration of antenna elements and transmission lines that are point-symmetrically disposed around a reference point.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If a power supply is used to superimpose information on retroreflected radio waves, then information can be transmitted, but manufacturing cost and weight increase
Solution Approach 1:
The antenna uses the incoming radio waves themselves as the power source to generate the modulated retroreflected waves. The rectenna converts received RF energy into DC voltage, which then drives the modulation process, eliminating the need for external power supplies or batteries.
Solution Approach 2:
The patent replaces the mechanical/electrical power supply system with an electromagnetic energy conversion system. Instead of using batteries or power adapters, the antenna harvests energy from the incoming radio waves through rectification and uses this energy to power the information modulation process.
2Loss of information
If a power supply is used to superimpose information on retroreflected radio waves, then information can be transmitted, but manufacturing cost increases
Solution Approach 1:
The antenna uses the incoming radio waves themselves as the power source to generate the modulated retroreflected waves. The rectenna converts received RF energy into DC voltage, which then drives the modulation process, eliminating the need for external power supplies or batteries.
Solution Approach 2:
The patent replaces the mechanical/electrical power supply system with an electromagnetic energy conversion system. Instead of using batteries or power adapters, the antenna harvests energy from the incoming radio waves through rectification and uses this energy to power the information modulation process.
3Loss of time
If passive notch filters are added to transmission lines, then information can be superimposed without power supply, but device complexity increases
Solution Approach 1:
The patent combines the notch filter functionality directly into the transmission line structure itself, rather than adding separate discrete filter components. This integration approach reduces overall device complexity while achieving the desired frequency selective modulation effect.
Solution Approach 2:
The transmission lines serve multiple functions: they provide the standard Van Atta array signal path for retroreflection and simultaneously incorporate the notch filter functionality for information modulation. This multi-functionality reduces the need for separate components and simplifies the overall structure.
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
Enables retroreflection of radio waves with superimposed information while reducing manufacturing costs and weight by eliminating the need for power supplies, facilitating easy distinction between reflections using radar devices.
Implementation Method 1
a passive notch filter, in which the antenna main body includes a plurality of pairs of antenna elements, and a plurality of transmission lines provided corresponding to the plurality of pairs of antenna elements
Implementation Method 2
an antenna main body for retroreflecting incoming radio waves; each pair of antenna elements in the plurality of pairs of antenna elements is disposed point-symmetrically with respect to a reference point in the antenna main body
Data Source
AI summary
A retroreflective antenna according to one embodiment includes: an antenna main body for retroreflecting incoming radio waves; and a passive notch filter, in which the antenna main body includes a plurality of pairs of antenna elements, and a plurality of transmission lines provided corresponding to the plurality of pairs of antenna elements, each pair of antenna elements in the plurality of pairs of antenna elements is disposed point-symmetrically with respect to a reference point in the antenna main body, each of the plurality of transmission lines connects corresponding pair of antenna elements among the plurality of pairs of antenna elements, electrical lengths of the plurality of transmission lines are the same, and the passive notch filter is provided in at least one transmission line among the plurality of transmission lines.