RF Circuit Switch Configuration for FDD Filter Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In high power class applications for frequency division duplex (FDD) bands, there is an increased loss in transmission and reception filters, which affects the efficiency of radio frequency circuits in mobile communication systems.
Innovation Solution
A radio frequency circuit design that includes filters for transmission and reception bands and a switch configuration allowing for different connection modes to reduce isolation requirements between filters, enabling efficient signal transmission and reception while minimizing loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If high power classes are applied to FDD bands, then maximum output power is increased, but isolation between transmission filter and reception filter becomes insufficient causing loss increase
Solution Approach 1:
The patent applies dynamics by making the connection configuration dynamic through a switch that can change between different connection modes (first connection mode for high power class with temporal separation, second connection mode for low power class with simultaneous connection). This allows the system to adapt its isolation mechanism based on the power class being used, resolving the contradiction between high output power and low filter loss.
Solution Approach 2:
The patent segments the connection configuration into distinct modes: a first connection mode that temporally separates transmission and reception paths for high power class, and a second connection mode that allows simultaneous connection for low power class. This segmentation enables the system to apply appropriate isolation strategies selectively, maintaining low filter loss while achieving high output power when needed.
2Reliability
If high isolation between transmission filter and reception filter is required, then transmission and reception can be separated, but device complexity increases
Solution Approach 1:
The switch component performs multiple functions: it acts as a simple connection element in low power class mode, and as an isolation mechanism in high power class mode. By making the switch multi-functional, the patent avoids adding dedicated isolation components, thereby maintaining reliability through temporal separation while minimizing the increase in device complexity.
3Reliability
If temporal separation of transmission and reception is implemented, then filter isolation is improved, but loss of time occurs
Solution Approach 1:
The patent makes the temporal separation dynamic rather than continuous. The switch transitions between connection modes based on power class requirements, allowing simultaneous transmission and reception when in low power class mode. This dynamic approach minimizes temporal separation delays while maintaining filter isolation only when necessary for high power class operation.
Data Source
AI summary
A radio frequency circuit includes an antenna connection terminal, an input terminal, an output terminal, a filter having a pass band including at least part of a transmission band of Band A for FDD, a filter having a pass band including at least part of a reception band of the Band A, and a switch that includes terminals. The antenna connection terminal is connected to the terminal. The filter is connected between the terminal and the input terminal. The filter is connected between the terminal and the output terminal. The switch is configured to switch between first connection, second connection, and third connection. In the first connection, the terminal is connected to the terminal and the terminal is not connected to the terminal. In the second connection, the terminal is connected to the terminal and the terminal is not connected to the terminal.