RF Matching Circuit With Bandpass Filter and Wave Trap Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current radio frequency amplification circuits in mobile communication systems face challenges in effectively suppressing harmonics and low-frequency spurious noise, which affect communication quality due to insufficient harmonic suppression capability and complex circuit designs.
Innovation Solution
A matching circuit comprising a first impedance matcher, a bandpass filter, and a wave trap, specifically designed to suppress second and third-order harmonics and low-frequency spurious noise, utilizing resonators and inductors/capacitors configurations to resonate at targeted frequencies within the 1.710 GHz-1.785 GHz and 1.850 GHz-1.910 GHz frequency bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the transmit power of the power amplifier is increased to meet higher power requirements, then the power output is improved, but the harmonics and spurious metrics worsen
Solution Approach 1:
The patent converts the harmful harmonics and spurious signals generated by high-power amplification into beneficial suppression targets by designing resonators and wave traps that specifically target these frequency components. The resonators are tuned to resonate at harmonic frequencies (e.g., 2nd, 3rd harmonics) to absorb and suppress these harmful signals, while the wave traps are configured to reject spurious emissions, thereby transforming the problem of harmful emissions into a solution that actively eliminates them.
Solution Approach 2:
The patent introduces intermediate filtering components (resonators and wave traps) between the power amplifier and the output to mediate the harmful effects. These intermediate elements act as mediators that selectively pass the desired fundamental frequency while blocking harmonics and spurious signals, allowing the system to maintain high transmit power without directly transmitting the harmful byproducts.
2Object-generated harmful factors
If conventional matching circuits are used to suppress harmonics, then some suppression is achieved, but the harmonic suppression capability and low-frequency spurious suppression capability remain insufficient
Solution Approach 1:
The patent segments the harmonic suppression function into multiple specialized components: resonators for suppressing specific harmonic frequencies (2nd, 3rd harmonics), wave traps for rejecting spurious signals, and matching networks for impedance transformation. Each segment is independently optimized for its specific frequency range and suppression target, allowing comprehensive coverage of different harmful frequency components that a single conventional filter cannot address.
Solution Approach 2:
The patent applies local quality by designing each resonator and wave trap with specific quality factors (Q-values) optimized for their respective frequency targets. The resonators have high Q-values for narrowband suppression at specific harmonic frequencies, while the wave traps have broader bandwidth characteristics for spurious rejection. This localized optimization of suppression characteristics at different frequency points achieves superior overall suppression performance.
3Object-generated harmful factors
If complex circuits are designed to meet technical requirements for harmonic suppression, then suppression capability is improved, but the circuit complexity increases and implementation becomes difficult
Solution Approach 1:
The patent merges multiple suppression functions into a single integrated matching circuit structure. The resonators, wave traps, and matching networks are combined in a cascaded configuration where the output of one stage feeds into the next, creating a unified circuit that performs impedance matching, harmonic suppression, and spurious rejection simultaneously. This integrated approach reduces the number of separate components and simplifies implementation compared to using multiple independent filters.
Solution Approach 2:
The patent designs the matching circuit to be multi-functional, serving both impedance matching and harmonic/spurious suppression functions. The resonators and wave traps are configured to work together with the matching network, allowing a single circuit structure to perform multiple tasks that would traditionally require separate components, thereby reducing overall circuit complexity while maintaining comprehensive suppression capability.
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 matching circuit effectively suppresses in-band harmonics and low-frequency spurious noise, improving communication quality by reducing interference from GSM frequency band signals while maintaining a simple and easy-to-implement structure.
Implementation Method 1
The first resonator and the second resonator are resonated in series at the second frequency and a frequency of a first harmonic signal of the signal of the first frequency
Implementation Method 2
the first bandpass filter enables a signal of the first frequency to pass through, and suppresses at least one of a signal of a second frequency and a signal of third harmonic generation of the first frequency
Implementation Method 3
The first wave trap is bridged between a rear end of the first impedance matcher and the ground, to suppress a signal of second harmonic generation of the first frequency
Implementation Method 4
An impedance of the first impedance matcher is a first preset impedance at a first frequency
Data Source
AI summary
A matching circuit, a radio frequency front-end power amplification circuit, and a mobile communication device are provided. The matching circuit is configurable for the radio frequency front-end power amplification circuit, including a first impedance matcher, a first bandpass filter, a first wave trap, and a first matching unit. An impedance of the first impedance matcher is a first preset impedance at a first frequency, the first bandpass filter is bridged between a front end of the first impedance matcher and ground, the first bandpass filter enables a signal of the first frequency to pass through, and suppresses at least one of a signal of a second frequency and a signal of third harmonic generation of the first frequency. The second frequency is lower than the first frequency. The first wave trap is bridged between a rear end of the first impedance matcher and the ground.