Built-In RF Test Signal Mixing for Fast oP1 dB Measurement
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Solution Overview
Problem
In radio frequency communication systems using amplitude modulation, measuring the output 1 dB compression point (oP1 dB) is time-consuming due to the need for external testing signal sources and signal distortion caused by non-linearity, which increases error-signal rates.
Innovation Solution
A wireless communication apparatus with a built-in testing signal generation system, comprising a direct current generator, an oscillating signal generator, a mixer, and an amplifying module, generates a sinusoidal wave for testing by mixing a direct current signal with an oscillating signal when in test mode, allowing for internal signal generation and measurement without external sources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an external testing signal source is added to measure oP1 dB, then measurement capability is improved, but testing time and device complexity increase
Solution Approach 1:
The patent merges the testing signal source function into the transmitter IC itself by using the local oscillating signal already present in the device. Instead of requiring an external signal source, the system uses its own internal oscillating signal mixed with a direct current signal to generate the testing sinusoidal wave, thereby eliminating external equipment and reducing testing time
Solution Approach 2:
The transmitter IC performs self-testing by generating its own testing signal through internal components (oscillating signal generator and mixer). The device uses its own local oscillating signal and mixes it with a direct current signal to create the required sinusoidal testing wave, making the system self-sufficient and eliminating dependency on external testing equipment
2Measurement precision
If sinusoidal signals with varied amplitude are inputted to measure Pout, then measurement accuracy is improved, but measurement complexity and time increase
Solution Approach 1:
The patent changes the approach from varying input amplitude to varying direct current signal levels. Instead of inputting sinusoidal signals with different amplitudes, the system mixes a constant oscillating signal with directly controllable DC signals of different amplitudes, simplifying the measurement procedure while maintaining accuracy in determining the oP1 dB point
3Measurement precision
If external testing equipment is used, then testing capability is improved, but system complexity and cost increase
Solution Approach 1:
The patent combines multiple functions (oscillating signal generation, signal mixing, and testing) into the existing transmitter IC structure. The local oscillating signal generator and mixer, which are already part of the transmitter, are utilized to generate testing signals, eliminating the need for separate external testing equipment and reducing overall system complexity
Solution Approach 2:
The transmitter's existing components serve dual purposes: the local oscillating signal generator and mixer are used both for normal transmission operations and for generating testing signals. This multi-functionality allows the same hardware to perform both communication and self-testing tasks, reducing the need for additional dedicated testing equipment
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 method reduces testing time by enabling fast and simple measurement of oP1 dB, ensuring consistent saturated power across wireless communication apparatus and verifying the frequency of oscillating signals without external signal sources, thereby improving testing efficiency.
Implementation Method 1
a mixer, coupled to the oscillating signal generator, for mixing one of the direct current signal and the transmitting signal with the oscillating signal according to a mode signal and generating a mixed signal
Data Source
AI summary
A wireless communication apparatus has: a direct current generator, for generating a direct current signal and a transmitter. The transmitter includes: an oscillating signal generator for generating an oscillating signal; a mixer for mixing one of the direct current signal and the transmitting signal with the oscillating signal according to a mode signal and generating a mixed signal; and an amplifying module for amplifying the mixed signal to generate an output signal. When the mode signal is represented that the wireless communication apparatus is under test, the direct current signal is being mixed with the oscillating signal and the mixed signal is a sinusoidal wave. When the mode signal is represented that the wireless communication apparatus is under transmitting, the transmitting signal is being mixed with the oscillating signal and the mixed signal is a modulated signal.