Radio-frequency module phase circuit isolation
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Solution Overview
Problem
As radio-frequency modules shrink in size, the isolation between transmission paths for multiple communication bands decreases, leading to potential electromagnetic coupling and reduced performance.
Innovation Solution
Incorporating phase circuits to adjust impedance matching and phase shifts on Smith charts for radio-frequency signals, along with strategically placing duplexers and SAW filters, to enhance isolation between transmission paths, and using a multilayer body with dielectric layers and conductive patterns to maintain effective separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the size of the multilayer body is decreased, then the size of the radio-frequency module is reduced, but the isolation between transmission paths decreases
Solution Approach 1:
The patent applies local quality by creating asymmetric ground connection configurations for different transmission paths. Specifically, the first transmission path has a first ground connection with specific impedance characteristics, while the second transmission path has a second ground connection with different impedance characteristics. This local differentiation of ground connection properties allows each transmission path to be optimized independently, maintaining high isolation between paths even when the overall module size is reduced.
Solution Approach 2:
The patent employs parameter changes by varying the impedance characteristics of ground connections for different transmission paths. The first ground connection is designed with specific impedance parameters optimized for the first transmission path, while the second ground connection has different impedance parameters optimized for the second transmission path. This parameter differentiation enables the maintenance of transmission path isolation despite miniaturization of the multilayer body.
2Area of stationary object
If the distance between external-connecting lands is reduced, then the area of the multilayer body is decreased, but electromagnetic coupling between transmission paths increases
Solution Approach 1:
The patent applies local quality by providing different ground connection configurations at different locations on the multilayer body. The first ground connection is specifically designed for the first transmission path with impedance characteristics optimized for that path, while the second ground connection is designed for the second transmission path with different impedance characteristics. This localized optimization prevents electromagnetic coupling even when external-connecting lands are placed close together.
Solution Approach 2:
The patent uses ground connections as intermediary elements that mediate between the transmission paths and the reference potential. By designing specific ground connection structures with controlled impedance characteristics, the patent creates effective electromagnetic shielding and reference planes that prevent harmful coupling between closely spaced transmission paths, allowing area reduction without sacrificing isolation.
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
Significantly reduces or prevents the decrease in isolation between transmission paths, even when frequency bands overlap, thereby maintaining effective signal transmission and reception across multiple communication bands.
Implementation Method 1
Phase adjustment is made in the first-transmission-path phase circuit so that impedance matching is maintained in a frequency band of a first radio-frequency signal which is transmitted through the first transmission path. Phase adjustment is made in the first-transmission-path phase circuit so that a phase of a frequency band of a second radio-frequency signal transmitted through the second transmission path in relation to impedance characteristics of the first transmission path shifts to an open side on a Smith chart.
Implementation Method 2
The multilayer body is constituted by dielectric layers stacked on each other having circuit patterns formed thereon. The transmitting-signal input terminals and the received-signal output terminals are realized by external-connecting lands arranged on the back surface of the multilayer body.
Data Source
AI summary
A radio-frequency module includes duplexers and a phase circuit. A first transmitting-signal input terminal is connected to the duplexer, while a second transmitting-signal input terminal is connected to the duplexer. The phase circuit is connected between the first transmitting-signal input terminal and the duplexer. The phase circuit performs phase adjustment so that impedance matching between the first transmitting-signal input terminal and the duplexer is performed in the fundamental frequency band of a first transmitting signal, and so that the phase of the frequency band of a second transmitting signal in relation to the impedance characteristics of a first transmission path which ranges from the first transmitting-signal input terminal to the duplexer with the phase circuit provided therebetween appears in an open side on a Smith chart.