MIMO Base Station Duplexer Path Change Unit Isolation
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Solution Overview
Problem
Existing base station duplexer designs face challenges in achieving high isolation between transmitted and received signals while maintaining a compact and lightweight structure, as increasing isolation through filter improvements leads to larger and heavier devices.
Innovation Solution
Incorporating a path change unit with circulators and dual-function filters in a 2T2R MIMO system, where the reception filter processes signals from one path and the transmission filter processes signals from another, allowing additional isolation through antenna orthogonality and reduced resonator and notch structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the number of stages of transmission filter and reception filter is increased to improve isolation between transmitted and received signals, then isolation is improved, but the size of filters increases
Solution Approach 1:
The patent combines the functions of transmission filter and reception filter into a single duplexer structure. The T-junction connects both filters to a common antenna interface, allowing the system to achieve high isolation through the combined filtering action rather than requiring separate filter stages for each function.
Solution Approach 2:
The duplexer structure serves multiple functions simultaneously: it provides both transmission filtering and reception filtering capabilities through a single integrated unit. The T-junction configuration allows the same hardware structure to handle both transmitted and received signal paths with appropriate filtering.
2Reliability
If the number of notches at isolated frequency is increased to improve isolation between transmitted and received signals, then isolation is improved, but manufacturing difficulty increases
Solution Approach 1:
The patent merges the isolation function into the duplexer structure itself rather than requiring additional notch filters. The T-junction configuration with transmission and reception filters working together provides the necessary isolation through their combined frequency selective properties.
Solution Approach 2:
The duplexer structure provides multiple functions including filtering, isolation, and signal routing through a single integrated design. This multi-functional approach eliminates the need for separate notch filtering components that would complicate manufacturing.
3Reliability
If filtering characteristics are improved to increase isolation between transmitted and received signals, then isolation is improved, but the weight of duplexer increases
Solution Approach 1:
The patent combines transmission and reception filtering functions into a single integrated duplexer unit with T-junction topology. This consolidation achieves high isolation through the synergistic interaction of the filters rather than requiring multiple separate filter assemblies that would increase weight.
Solution Approach 2:
The duplexer structure provides multiple functions including signal filtering, isolation, and path switching through a single lightweight unit. This multi-functional integration eliminates the need for additional heavy components that would be required if isolation were achieved through separate filter stages.
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 configuration achieves additional isolation of 30 dB to 50 dB between transmitted and received signals, enabling smaller and lighter duplexer designs that meet high performance standards without increasing size or weight.
Implementation Method 1
The first and second antennas 100 and 101 are arranged to generate polarized waves orthogonal to each other
Implementation Method 2
a transmission filter (Tx0) 204 and a reception filter (Rx0) 206, which process a transmitted signal and a received signal for the first path P0, respectively, are connected using a T-junction 202
Data Source
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AI summary
A base station apparatus of mobile communication system is provided, including an antenna system including first antenna for transceiving signals for a first path among MIMO paths, and a second antenna for transceiving signals for a second path among the MIMO paths, a first duplexer including transmission filter for processing the transmitted signal of first path and reception filter for processing the received signal of second path, a second duplexer including reception filter for processing the received signal of first path and transmission filter for processing the transmitted signal of second path, and a path change unit for providing the transmitted signal provided from the first duplexer to the first antenna and the received signal provided from the first antenna to the second duplexer and to provide the transmitted signal from the second duplexer to the second antenna and the received signal from the second antenna to the first duplexer.