RF Front End Signal Isolation via Coupler-Based Cancellation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional RF front end circuitry faces challenges in achieving adequate primary RF transmit signal isolation in the secondary receiver signal path due to antenna-to-antenna coupling, which degrades the performance of secondary RF receive signals.
Innovation Solution
The RF front end circuitry incorporates a primary signal coupler and secondary signal coupler to reuse existing cross-coupling connection lines for delivering a portion of the primary RF transmit signals to the secondary receiver circuitry, allowing for cancellation of primary RF transmit signals in the secondary receiver path without adding additional long signal lines, thereby enhancing signal isolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional RF front end circuitry uses cross-coupling connection lines for antenna switching, then antenna swapping capability is achieved, but primary RF transmit signals couple into the secondary receiver path through these same lines, degrading signal isolation
Solution Approach 1:
The patent extracts the harmful primary RF transmit signals from the secondary receiver path by using signal couplers to identify and remove these coupled signals, preventing them from degrading the receiver performance
Solution Approach 2:
The patent implements feedback by using signal couplers to monitor the secondary receiver path for coupled primary RF transmit signals, then feeding this information back to the signal processing circuitry which generates cancellation signals to neutralize the harmful coupling
2Object-affected harmful factors
If additional signal lines are added to deliver primary RF transmit signals to secondary receiver circuitry for cancellation purposes, then signal isolation is improved, but device complexity and circuit board space requirements increase
Solution Approach 1:
The patent makes the existing cross-coupling connection lines serve dual purposes: maintaining their original antenna switching function while simultaneously serving as signal paths for delivering primary RF transmit signals to the secondary receiver circuitry for cancellation, eliminating the need for separate dedicated signal lines
Solution Approach 2:
The patent combines the antenna switching function and the signal cancellation function into a single integrated system, where the same physical infrastructure (cross-coupling connection lines) supports both operations, reducing overall system complexity
Data Source
AI summary
RF front end circuitry includes primary transceiver circuitry associated with a primary antenna and secondary receiver circuitry associated with a secondary antenna. Generally, the primary transceiver circuitry and the primary antenna are located on one end of a mobile communications device, while the secondary receiver circuitry and the secondary antenna are located at an opposite end of the device. Cross-coupling connection lines run between the antenna switching circuitry for the primary antenna and the secondary antenna, and are reused to send a portion of primary RF transmit signals from the primary transceiver circuitry to the secondary receiver circuitry so that primary RF transmit signals coupled into the secondary receiver path via antenna-to-antenna coupling can be reduced.