Multi-Band RF Filter Layout With Asymmetric Uplink Attenuation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional radio frequency circuits for multi-band communication require an increased number of filters, leading to larger front-end circuits.
Innovation Solution
A radio frequency circuit design that incorporates a combination of filters with specific passbands and switches to support multiple frequency bands, including filters for uplink and downlink bands, with asymmetrical attenuation slopes to minimize filter count.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple filters are incorporated to support multi-band functionality, then communication capability across multiple frequency bands is improved, but the number of filters increases and circuit size becomes larger
Solution Approach 1:
The first filter is designed to handle both uplink bands of different frequency bands simultaneously, making a single filter perform multiple functions that would traditionally require separate filters. This reduces the total filter count while maintaining multi-band communication capability.
Solution Approach 2:
The patent combines the functions of multiple filters into a unified filter structure where the first filter processes uplink signals across multiple bands, and downlink filters handle downlink signals. This merging approach reduces component count while preserving spectral separation and communication performance.
2Adaptability or versatility
If multiple filters are incorporated to support multi-band functionality, then communication capability across multiple frequency bands is improved, but circuit size becomes larger
Solution Approach 1:
The first filter serves multiple uplink bands simultaneously, reducing the number of filter components needed and consequently decreasing the overall circuit area occupied by the front-end filtering structure.
Solution Approach 2:
By merging multiple filtering functions into a consolidated filter architecture with strategic asymmetrical attenuation, the physical footprint of the front-end circuit is reduced while maintaining support for multiple frequency bands.
3Reliability
If asymmetrical attenuation slope is applied to the first filter, then spectral separation between uplink and downlink bands is improved, but filter design complexity increases
Solution Approach 1:
The first filter employs an asymmetrical attenuation slope where the attenuation characteristic differs between the lower frequency side and the higher frequency side of the passband. This asymmetry optimizes spectral separation for specific band combinations, improving reliability by enhancing signal isolation where most needed while managing design complexity through targeted rather than uniform complexity distribution.
Data Source
AI summary
A radio frequency circuit includes: a first filter having a passband including uplink bands of first and second bands (UL1,UL2); a second filter having a passband including a downlink band of the first band (DL1); and a downlink filter arrangement that filters a downlink band of the second band (DL2) and a downlink band of a third band (DL3). All filter paths are ultimately communicatively coupled to an antenna terminal, either directly or via a switch. The combination of the first and second bands is a band combination for simultaneous communication. The frequency ordering is DL2>DL3>UL2>UL1>DL1. The first filter has a steeper attenuation slope on a higher frequency side than on a lower frequency side of the passband.