High-Frequency Power Amplifier Circuit for Intermodulation Suppression
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Solution Overview
Problem
Existing high-frequency circuits experience degradation in receiving sensitivity due to intermodulation distortion when simultaneously transmitting and receiving multiple high-frequency signals, causing interference with the reception band.
Innovation Solution
A high-frequency circuit design incorporating a first filter for the transmission band of a first communication band, a second filter for a different transmission band, and a third filter for the reception band, along with a power amplifier configuration using a differential amplifier and transformer coils to suppress intermodulation distortion by converting and combining signals effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple high-frequency signals are simultaneously transmitted and received, then communication versatility is improved, but receiving sensitivity deteriorates due to intermodulation distortion
Solution Approach 1:
The patent divides the power amplifier into multiple independent amplifying elements (first amplifying element, second amplifying element, etc.), each handling specific frequency bands. This segmentation prevents intermodulation distortion between different frequency bands by isolating their amplification paths, thus maintaining receiving sensitivity while enabling multi-band communication versatility.
Solution Approach 2:
The patent introduces an output converter (transformer with first coil and second coil) as an intermediary component between amplifying elements and the output terminal. This intermediary converts and combines signals from multiple amplifying elements while suppressing intermodulation distortion, allowing simultaneous transmission of multiple high-frequency signals without degrading receiving sensitivity.
2Device complexity
If a conventional power amplifier configuration is used, then device complexity is reduced, but intermodulation distortion increases causing reception interference
Solution Approach 1:
The power amplifier is segmented into multiple amplifying elements (first amplifying element, second amplifying element) that operate independently for different frequency bands. This segmentation structure increases device complexity slightly but effectively suppresses intermodulation distortion by preventing interaction between different frequency signals during amplification.
Solution Approach 2:
An output converter (transformer) is introduced as an intermediary component that combines signals from multiple amplifying elements. This intermediary device manages the complexity by providing a structured method to combine signals while suppressing intermodulation distortion, preventing reception interference.
3Adaptability or versatility
If filters for multiple bands are implemented, then communication band coverage is improved, but circuit complexity increases
Solution Approach 1:
The patent employs a universal power amplifier structure with multiple amplifying elements that can handle different frequency bands. Each amplifying element is designed to be multi-functional, capable of operating across various bands, which reduces the need for completely separate amplifier circuits for each band, thus managing circuit complexity while improving band coverage.
Solution Approach 2:
The circuit is segmented into specialized components: filters for specific bands (first filter, second filter, third filter) and amplifying elements for specific bands. This segmentation allows each component to be optimized for its function while maintaining overall manageable complexity through modular design.
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 solution effectively reduces intermodulation distortion, thereby preventing degradation of receiving sensitivity and allowing simultaneous transmission and reception across multiple communication bands.
Implementation Method 1
an output converter that is a first transformer including a first coil and a second coil. One end of the first coil is connected with an output of the first amplifying element, the other end of the first coil is connected with an output of the second amplifying element
Data Source
AI summary
A high-frequency circuit includes a power amplifier for a communication band A, and a power amplifier for a communication band B. Transmission in the communication band A, transmission in the communication band B, and reception in the communication band C can be simultaneously used. A frequency range of intermodulation distortion generated between a second harmonic wave of a transmission signal of the communication band A and a fundamental wave of a transmission signal of the communication band B, overlaps with at least part of a reception band of the communication band C. The power amplifier includes amplifying elements and an output trans including coils. One end of the coil is connected with an output of the amplifying element, the other end of the coil is connected with an output of the amplifying element, and one end of the coil is connected with an output terminal of the power amplifier.