RF Front-End Circuit Layout for Overlapping Filter Isolation
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Solution Overview
Problem
The existing front-end circuit configurations face challenges in achieving sufficient isolation between filters with overlapping passbands, leading to difficulties in simultaneously transferring radio frequency signals.
Innovation Solution
A front-end circuit design incorporating a power divider that splits radio frequency signals into two paths, each connected to filters with overlapping passbands, ensuring favorable isolation and low-noise amplification to enable simultaneous signal transfer without power attenuation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a multiplexer is simply disposed upstream of the filters, then the device complexity is reduced, but the isolation between filters with overlapping passbands becomes insufficient
Solution Approach 1:
The invention divides the signal path into multiple independent branches, each containing a filter, with a power divider at the input and a combiner at the output. This segmentation allows each filter to operate independently with its own signal path, achieving sufficient isolation between filters with overlapping passbands while maintaining a relatively simple overall structure.
Solution Approach 2:
The power divider and combiner act as intermediary components that separate and then recombine the signal paths. The power divider splits the input signal into multiple paths with specific isolation characteristics, and the combiner recombines the filtered signals at the output, providing the necessary isolation between filters without requiring complex filtering networks.
2Device complexity
If filters with overlapping passbands are connected directly to the antenna via a multiplexer, then the device complexity is reduced, but the ability to simultaneously transfer radio frequency signals is compromised
Solution Approach 1:
By segmenting the signal path into separate branches for each filter, the invention enables simultaneous processing of multiple frequency bands. Each filter operates on its own dedicated path from the power divider to the combiner, allowing concurrent transfer of radio frequency signals with overlapping passbands without mutual interference.
Solution Approach 2:
The invention transitions from a single-dimensional sequential signal path to a multi-dimensional parallel architecture. Multiple signal paths operate simultaneously in different spatial dimensions within the circuit, enabling concurrent signal transfer through different filters while maintaining isolation through the power divider and combiner structure.
3Ease of manufacture
If a simple multiplexer configuration is used, then the ease of manufacture is improved, but the signal quality and isolation performance deteriorate
Solution Approach 1:
The segmented architecture with independent filter branches allows each component to be optimized and manufactured separately with standard isolation specifications. The power divider and combiner provide built-in isolation characteristics that do not require precision matching between filters, simplifying the manufacturing process while maintaining adequate isolation performance.
Solution Approach 2:
The power divider and combiner serve as intermediary components that provide isolation through their inherent circuit characteristics rather than relying on precise filter matching. This approach allows the use of standard off-the-shelf filters without requiring tight tolerance control, improving ease of manufacture while maintaining sufficient isolation performance.
Data Source
AI summary
A front-end circuit includes: a power divider that performs power division on a radio frequency signal inputted to an input terminal, using a predetermined division ratio, and outputs resultant radio frequency signals from output terminals; a filter connected to one of the output terminals and having a first passband; and a filter connected to the other of the output terminals and having a second passband having a frequency range that at least overlaps a frequency range of the first passband.