Separate I/Q Power Amplification for Mobile Wireless Devices
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Solution Overview
Problem
Mobile wireless communications devices face interference issues due to unwanted reception of conducted or radiated energy from power amplifiers and other components, leading to degradation of total radiated power (TRP) and harmonic interference, particularly in GSM systems and with In-phase (I) and Quadrature (Q) modulation schemes.
Innovation Solution
The implementation of a 3 dB power combiner as a quadrature hybrid power combiner, separate power amplifier circuits for In-phase and Quadrature signals, and the use of a ferrite-based RF filter near battery charging contacts to minimize harmonic emission and improve antenna matching, along with an optimized antenna contact design that reduces RF inductance and variation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate power amplifier circuits are used for In-phase and Quadrature signals, then linearity and TRP are improved, but device complexity increases
Solution Approach 1:
The patent divides the single power amplifier circuit into two separate power amplifier circuits, one for the In-phase (I) signal and another for the Quadrature (Q) signal. This segmentation allows each amplifier to operate more linearly without interfering with the other, improving overall system linearity and total radiated power (TRP) performance while managing the complexity through modular design
2Volume of moving object
If power amplifiers are placed closer to reduce device size, then compactness is improved, but conducted energy interference and harmonic emission increase
Solution Approach 1:
The patent extracts and removes harmful conducted energy and harmonic emissions from the power amplifier circuits using filtering components. By taking out these harmful factors through dedicated filter circuits, the system can maintain compact component placement while preventing interference and harmonic emission from affecting other device components
Solution Approach 2:
The patent introduces filter circuits as intermediary elements between the power amplifiers and other device components. These intermediary filters act as mediators that block conducted energy and harmonic emissions while allowing the power amplifiers to operate at full power in the compact device layout
3Volume of moving object
If antenna and power amplifier are placed closer for miniaturization, then device size is reduced, but antenna matching and TRP degrade due to interference
Solution Approach 1:
The patent extracts harmful radiated energy and interference from the antenna using filtering components placed near the antenna connection. This allows the antenna to be positioned closer to the power amplifier for miniaturization while maintaining proper antenna matching and TRP performance by removing the interfering energy paths
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
This configuration enhances antenna matching, reduces harmonic emission, improves TRP, and increases battery life by using more linear power amplifiers and isolating the power amplifier from antenna impedance variations, while maintaining efficient digital modulation capabilities.
Implementation Method 1
use of a ferrite-based RF filter near battery charging contacts to minimize harmonic emission
Implementation Method 2
ferrite-based RF filter...minimize harmonic emission
Implementation Method 3
3 dB power combiner as a quadrature hybrid power combiner...separate power amplifier circuits for In-phase and Quadrature signals
Data Source
AI summary
A mobile wireless communications device includes a housing an antenna, and radio frequency (RF) circuitry. A transceiver is connected to the antenna and a processor is operative with the RF circuitry. The transceiver includes an In-phase and Quadrature (I/Q) Modulation and Power Amplification circuit having an In-phase (I) circuit with a modulator mixer and power amplifier circuit. A Quadrature (Q) circuit includes a modulator mixer and power amplifier circuit. A power combiner receives the separately amplified In-phase and Quadrature signals and sums and outputs the signals as a combined I and Q signal. The I and Q circuits are isolated from the combined I and Q signal to enhance antenna matching and transmitted radiated power (TRP) and reduce harmonic emission from the power amplification circuits.