Retroreflective Antenna Array for Passive RF Identification
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Solution Overview
Problem
Existing satellite and flying object identification systems require continuous signal transmission, which consumes power and increases size and complexity, posing challenges in reducing power requirements and improving efficiency.
Innovation Solution
The development of an antenna array comprising retroreflective antennas and a passive modulation circuit that passively receives, modulates, and reflects radiofrequency signals, eliminating the need for an active power source and enabling passive identification and information reception.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If continuous signal transmission is used for satellite identification, then reliable identification can be achieved, but power consumption increases and system size increases
Solution Approach 1:
The patent inverts the traditional active transmission approach by using passive reflection. Instead of the satellite actively transmitting identification signals, the ground station transmits signals that are passively reflected back by the satellite's retroreflective antenna array, eliminating the need for onboard power consumption while maintaining identification capability
Solution Approach 2:
The satellite system uses the ground station's transmitted signal as its own identification signal. The retroreflective antenna array automatically reflects the incoming signal back to the ground station without requiring any active components or power source on the satellite, achieving self-service identification
2Adaptability or versatility
If active communication systems are installed on satellites, then information transmission capability is improved, but device complexity and size increase
Solution Approach 1:
The patent extracts the active communication components (transmitters, power amplifiers, signal generators) from the satellite system and relocates them to the ground station. The satellite retains only the passive retroreflective antenna array, dramatically reducing onboard device complexity and size while maintaining bidirectional communication capability
Solution Approach 2:
The retroreflective antenna array serves multiple functions: it acts as both the identification reflector and the communication receiver/transmitter. The same passive structure that provides identification also enables information exchange by modulating the reflected signal, eliminating the need for separate active communication systems
3Use of energy by moving object
If passive reflection without modulation is used, then power requirements are reduced, but information transmission capability is lost
Solution Approach 1:
The patent introduces dynamic control to the passive reflection system through electronically controllable switches that modulate the reflected signal. These switches can dynamically change the reflection characteristics based on control signals from the ground station, enabling information encoding without requiring active power sources on the satellite
Solution Approach 2:
The patent introduces an intermediary modulation circuit between the retroreflective antenna array and the reflected signal. This circuit uses the incoming signal's own energy to control the switching elements, which then modulate the reflected signal to carry information back to the ground station, effectively using the signal itself as the power source for modulation
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 allows for efficient, power-free signal modulation and reflection, reducing the size and power requirements of satellite and flying object systems while enabling effective identification and information exchange.
Implementation Method 1
a plurality of retroreflective antennas configured to passively receive a radiofrequency (RF) signal from a source, and configured to reflect the RF signal
Implementation Method 2
a passive modulation circuit, electrically connected to the plurality of retroreflective antennas, configured to modulate the RF signal to represent a code
Data Source
AI summary
Antenna Array for passively modulating radio frequency signals. Specifically, an antenna array or system comprising a plurality of retroreflective antennas configured to passively receive a radiofrequency (RF) signal from a source, and configured to reflect the RF signal; and a passive modulation circuit, electrically connected to the plurality of retroreflective antennas, configured to modulate the RF signal to represent a code, wherein the code comprises information, and further comprising: a plurality of RF switches. Additionally, a method for passively reflecting modulated signals, comprising generating a radiofrequency (RF) signal at a source; receiving the a RF signal with a plurality of retroreflective antennas; passively modulating the signal's amplitude to create a modulated RF signal, wherein the modulated RF signal comprises a code, and wherein the code further comprises a unique identifier associated with the plurality of retroreflective antennas; and passively reflecting a modulated signal back to the source.