Indented Antenna Array for Full-Duplex Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Full-duplex radios face challenges in achieving sufficient transmitter-receiver isolation, as conventional methods like pattern diversity and circulators offer limited isolation, especially in space-conscious applications, and are ineffective against antenna reflection and mutual coupling.
Innovation Solution
The solution involves indenting an N-element antenna array from its broadside alignment to create a linear progressive phase delay between elements, adding transmission lines with progressive phase differences between circulators, which enhances isolation by breaking spatial symmetry and separating signal components with passive delay lines and a power combiner.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional antenna isolation methods (pattern diversity, circulators) are used, then transmitter-receiver isolation is achieved to some extent, but the isolation level is insufficient and limited
Solution Approach 1:
The patent applies asymmetry by indenting the antenna array elements from their conventional symmetric broadside alignment positions. Each element is offset by a specific distance and angle to create an asymmetric geometry that produces progressive phase delays across the array. This asymmetric configuration breaks the spatial symmetry that causes strong transmitter-to-receiver coupling, achieving up to 15 dB improvement in isolation over conventional symmetric arrangements.
Solution Approach 2:
The patent transitions from a conventional two-dimensional antenna array layout to a three-dimensional indented configuration. By adding the indentation dimension (offsetting elements from the broadside plane), the patent creates progressive phase delays in the spatial domain that enable better signal separation. This dimensional change allows the array to achieve superior isolation while maintaining full-duplex operation at the same frequency.
2Volume of moving object
If space-conscious applications use conventional isolation methods, then compact design is achieved, but isolation performance deteriorates
Solution Approach 1:
The indented antenna array uses asymmetric element positioning within a compact form factor. By offsetting elements from the broadside alignment in a controlled manner, the patent achieves high isolation performance without requiring large physical separation between transmitter and receiver antennas. This allows space-conscious applications to maintain both compact size and effective interference suppression.
3Object-affected harmful factors
If circulators are used for non-reciprocity, then limited isolation is achieved, but effectiveness against antenna reflection and mutual coupling is lost
Solution Approach 1:
The patent replaces circulator-based isolation with an asymmetric indented array configuration that inherently suppresses multiple interference mechanisms. The asymmetric geometry creates different phase delays for transmitted and received signals, as well as for reflected and coupled signals. This approach provides comprehensive isolation effectiveness against antenna reflection, mutual coupling, and direct leakage without relying on circulator non-reciprocity.
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 significantly reduces leakage power and mutual coupling, achieving up to 15 dB improvement in isolation, allowing for efficient full-duplex operation without limiting antenna polarization or radiation pattern choices.
Implementation Method 1
the tilting has a constant slope which is selected to create a linear progressive phase delay between each adjacent pair of elements of the N-element antenna array
Implementation Method 2
each transmission line has a linear progressive phase difference between each adjacent pair of elements of the N-element antenna array
Data Source
AI summary
An apparatus and method for enhancing full-duplex radio communications using an indented transmitter and receiver antenna. A multi-element antenna array is configured with each antenna coupled to a circulator that has connections to both a transmission path and a receiving path. The apparatus is configured with indentations that provide a tilting of the array from its broadside to create a progressive phase delay between adjacent pairs of elements. Transmitted and received waves travel a single trip through the indention, while antenna reflection or circulator leakage travels a round trip through indention, so that these signal components can be readily separated to achieve high levels of isolation during full-duplex transmitting and receiving.