RF Multiplexer Circuit Using Acoustic and LC Filters for Band Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In the context of 5G communication systems, existing multiplexers with LC filters struggle to maintain isolation between communication bands due to narrow frequency gaps and wide bandwidths, leading to increased propagation loss.
Innovation Solution
A radio frequency circuit design incorporating acoustic wave filters and LC filters connected in series, where acoustic wave filters provide steep attenuation slopes for high isolation between communication bands and LC filters ensure low loss and wide attenuation in passbands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If an LC filter is used to multiplex radio frequency signals in wide communication bands, then the passband bandwidth is increased, but the attenuation slopes at both ends of the passband become not steep, resulting in poor isolation between communication bands
Solution Approach 1:
The patent combines an acoustic wave filter and an LC filter in series to create a composite filter structure. The acoustic wave filter provides steep attenuation slopes for good isolation between bands, while the LC filter maintains wide passband bandwidth. This merging of two different filter technologies resolves the contradiction between bandwidth and isolation.
Solution Approach 2:
The patent uses a composite filtering structure combining acoustic wave resonators and LC circuit elements. This composite approach leverages the complementary strengths of acoustic wave filters (steep attenuation) and LC filters (wide bandwidth) to achieve both high isolation and wide passband simultaneously.
2Speed
If the frequency gap between two different communication bands is narrow, then the communication system can use higher frequency bands, but the propagation loss of radio frequency signals increases due to insufficient isolation
Solution Approach 1:
By merging acoustic wave filter and LC filter in series, the system achieves steep attenuation characteristics that provide sufficient isolation even when frequency gaps between bands are narrow. This reduces signal leakage and propagation loss while enabling use of higher frequency bands for faster communication.
3Device complexity
If a multiplexer includes only an LC filter, then the device complexity is low, but the attenuation slopes are not steep enough to ensure isolation between communication bands
Solution Approach 1:
The patent merges acoustic wave filter and LC filter components in series. While this increases device complexity compared to using only an LC filter, it achieves the necessary steep attenuation slopes for reliable isolation between communication bands, which is critical for 5G multi-band operation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The proposed solution effectively demultiplexes radio frequency signals with high isolation and low loss across communication bands, even when bandwidths are wide and frequency gaps are narrow, enhancing signal propagation in 5G systems.
Implementation Method 1
a first acoustic wave filter that is connected to the common terminal and includes a first acoustic wave resonator
Implementation Method 2
a first LC filter that is connected to the common terminal via the first acoustic wave filter and includes at least one of an inductor or a capacitor
Implementation Method 3
a first LC filter that is connected to the common terminal via the first acoustic wave filter and includes at least one of an inductor or a capacitor
Data Source
AI summary
A radio frequency circuit includes a first acoustic wave filter that is connected to a common terminal and includes a first acoustic wave resonator, a first LC filter that is connected to the common terminal via the first acoustic wave filter and includes at least one of an inductor or a capacitor, a second acoustic wave filter that is connected to the common terminal and includes a second acoustic wave resonator, and a second LC filter that is connected to the common terminal via the second acoustic wave filter and includes at least one of an inductor or a capacitor.