Duplexer Module With Opposite-Side Filters To Prevent Isolation Deterioration
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Solution Overview
Problem
In multi-band duplexer modules, the reduced size makes it difficult to maintain sufficient spacing between transmission and reception signal lines, leading to deterioration of isolation between signal lines due to line coupling, especially when discrete components with integrated filters are used.
Innovation Solution
The duplexer module separates transmission and reception filters into distinct components arranged on opposite sides of the module substrate, increasing spacing between them and between interconnection lines, with a phase adjusting circuit positioned between the antenna, transmission, and reception lines to reduce insertion losses and prevent line crossing, thereby enhancing isolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If discrete components with integrated transmission and reception filters are used to reduce module size, then the duplexer module size is reduced, but the isolation between signal lines deteriorates due to insufficient spacing and line coupling
Solution Approach 1:
The patent divides the integrated filter component into separate transmission filter and reception filter components. The transmission filter is mounted on a first surface of the substrate while the reception filter is mounted on a second surface, physically separating the transmission and reception signal paths. This segmentation eliminates the line coupling problem that occurs when filters are integrated in a discrete component, thereby maintaining sufficient isolation between signal lines while still achieving compact module size through efficient space utilization.
2Volume of moving object
If transmission and reception filters are positioned closer together in integrated discrete components, then the module size is reduced, but the isolation between signal lines deteriorates due to increased coupling
Solution Approach 1:
The patent transitions from a two-dimensional planar arrangement of filters to a three-dimensional configuration by mounting the transmission filter and reception filter on opposite surfaces of the substrate. This dimensional change allows the filters to be positioned close to each other in terms of module footprint while maintaining sufficient physical spacing between them, thereby reducing line coupling effects and improving signal isolation without sacrificing module compactness.
3Volume of moving object
If interconnection lines are arranged in a crossing relationship to accommodate compact layout, then the module size is reduced, but the isolation between signal lines deteriorates
Solution Approach 1:
The patent segments the interconnection lines into separate groups that connect to different surfaces of the substrate. Transmission signal lines are routed to the first surface where the transmission filter is mounted, while reception signal lines are routed to the second surface where the reception filter is mounted. This segmentation of interconnection paths eliminates the need for crossing lines and maintains clear isolation between transmission and reception signal paths throughout the module.
Data Source
AI summary
A duplexer module that prevents degradation of isolation between signal lines includes transmission filters, reception filters, phase adjusting circuits, and a multilayer substrate. The transmission filters and the reception filters are constituted as separate discrete components. The multilayer substrate includes filter mount terminals to which the transmission filters are mounted, and filter mount terminals to which the reception filters are mounted. The filter mount terminals are arranged along an upper side of the multilayer substrate, and the filter mount terminals are arranged along a lower side of the multilayer substrate.