RF Interference Cancellation Using Beam and Omni Antennas
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing RF interference cancellation techniques, such as directional antennas, often fail to effectively suppress jamming signals, especially in military applications where interference can compromise mission success.
Innovation Solution
The use of a beam antenna pointed at the remote jammer, connected to a Division Free Duplex (DFD) RF canceller, and an omnidirectional antenna receiving both jamming and communication signals, with a controller processing these signals to generate a jamming-canceled output by subtracting the jamming signal from the wideband primary signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If directional antennas are used to minimize jamming signal strength, then the strength of undesired transmitter is reduced, but the signal power of desired transmitter is also reduced and performance is insufficient to overcome jammer
Solution Approach 1:
The system divides the antenna function into two separate antennas: a directional antenna specifically oriented toward the jammer to capture jamming signals, and an omnidirectional antenna to receive both desired and jamming signals. This segmentation allows each antenna to be optimized for its specific function, enabling effective jamming cancellation without compromising desired signal reception.
Solution Approach 2:
An intermediary processing system is introduced that receives signals from both antennas, processes them to extract and cancel the jamming component, and outputs the cleaned desired signal. This intermediary processing layer enables the system to separate and eliminate harmful jamming signals while preserving the desired communication signals.
2Measurement precision
If a beam antenna is pointed at the remote jammer to receive jamming signal, then jamming signal cancellation efficacy is improved to 70-75 dB, but the desired signal may be attenuated
Solution Approach 1:
The directional antenna is specifically optimized with its beam pattern oriented toward the jammer's location, creating a localized reception pattern that maximizes jamming signal capture in that specific direction while minimizing reception from other directions. This local quality optimization ensures high cancellation efficacy without broad-signal attenuation.
Solution Approach 2:
The system uses partial action by having the directional antenna focus only on receiving jamming signals from the specific jammer direction, rather than attempting to receive all signals omnidirectionally. This partial reception strategy allows the system to achieve sufficient jamming cancellation (70-75 dB) while the omnidirectional antenna simultaneously captures the desired signal with minimal attenuation.
3Power
If directional antenna system is used to maximize signal power of desired transmitter, then signal power is increased, but the ability to overcome deleterious effects of jammer is insufficient
Solution Approach 1:
The system converts the harmful jamming signal into a beneficial element by using the directional antenna to capture the jamming signal, processing it to extract its characteristics, and then using this processed jamming signal to generate an anti-jamming waveform that actively cancels the interference. The harmful jamming energy is thus transformed into a tool for its own cancellation.
Solution Approach 2:
The system performs preliminary anti-action by first capturing and processing the jamming signal through the directional antenna before the jamming interference can fully degrade the desired signal. The processed jamming information is used to pre-generate cancellation waveforms that are then applied to neutralize the jamming effect, preventing rather than merely responding to the interference.
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 approach achieves superior jamming signal cancellation with an efficacy of 70 to 75 dB, simplifying the orientation process by focusing on the jammer's location rather than the communication partner's, and maintaining a strong desired signal with less than 10 dB attenuation.
Implementation Method 1
The beam antenna is pointed at the remote jammer
Implementation Method 2
a controller processing these signals to generate a jamming-canceled output by subtracting the jamming signal from the wideband primary signal
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A communication system (80) includes an omnidirectional antenna (82), a beam antenna (84) and a controller (86). The omnidirectional antenna (82) receives a wideband primary signal and the beam antenna is oriented towards a jammer to receive a jamming signal. The controller (86) subtracts a processed jamming signal from a processed wideband primary signal to produce a jamming cancelled signal (88).