RF Filter Switching for Intermodulation-Safe Simultaneous Transmission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The electronic system described in Patent Document 1 experiences a reduction in reception sensitivity due to inter-modulation distortion (IMD) between radio frequency signals with different frequencies during simultaneous transmission.
Innovation Solution
A radio frequency circuit comprising multiple filters, power amplifiers, low-noise amplifiers, and switches, along with inductors and capacitors, is designed to manage inter-modulation distortion by separating and isolating frequency bands, thereby reducing interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple power amplifiers transmit signals in different communication bands simultaneously, then the communication capability is improved, but inter-modulation distortion occurs that overlaps with receive bands, reducing reception sensitivity
Solution Approach 1:
A switch is introduced as an intermediary component between the power amplifiers and filters. This switch selectively connects or disconnects specific power amplifiers to specific filters based on the communication band being used, preventing inter-modulation distortion from affecting receive bands while maintaining simultaneous transmission capability across multiple bands
Solution Approach 2:
The system dynamically configures connections between power amplifiers and filters using the switch. Depending on which communication bands are actively transmitting, the switch dynamically routes signals to appropriate filters or disconnects them, adaptively managing the transmission paths to avoid generating harmful inter-modulation products in receive bands
Data Source
AI summary
Reduction of reception sensitivity, which is caused by inter-modulation distortion occurring between a first transmit signal and a second transmit signal, is suppressed. A first filter has a passband including the transmit band of a first communication band. A second filter has a passband including the transmit band of a second communication band. A third filter has a passband including the receive band of the first communication band. The first communication band and the second communication band are communication bands available for simultaneous transmission. At least a part of the frequency range of the inter-modulation distortion, which occurs between the first transmit signal in the first communication band and the second transmit signal in the second communication band, overlaps at least a part of the receive band of the first communication band.