TORP Signal Generator Modulation With Coherent Amplitude Control
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Solution Overview
Problem
Existing signal modulation technologies, such as those using injection-locked oscillators, face limitations in generating both phase and amplitude modulations efficiently, as they are sensitive to manufacturing variations and temperature changes, and require complex control signals, making them unsuitable for direct digital baseband modulation.
Innovation Solution
A device employing multiple TORP signal generators synchronized by a single digital baseband signal, where each generator produces a high-frequency signal through frequency synthesis, allowing for direct amplitude and phase modulation without the need for complex control inside the generators, and enabling coherent linear combination of signals to achieve phase and amplitude modulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If injection-locked oscillators are used to generate phase modulation by changing self-oscillation frequency, then phase modulation is achieved, but the system becomes sensitive to manufacturing variations and temperature changes
Solution Approach 1:
The patent replaces the traditional injection-locked oscillator mechanism (which relies on frequency pulling and self-oscillation) with a direct digital synthesis approach using a numerically controlled oscillator (NCO) and digital signal processing. This substitution eliminates the sensitivity to manufacturing variations and temperature changes by using purely digital frequency and phase control, where the output frequency is determined by a digital counter rather than analog oscillator characteristics.
Solution Approach 2:
The patent changes the control parameter from analog frequency adjustment (which is sensitive to environmental variations) to digital parameter control. The phase and frequency are controlled by digital words stored in lookup tables and processed by digital counters, making the system immune to temperature and manufacturing variations while maintaining precise phase modulation capability.
2Adaptability or versatility
If complex control signals are applied to ILO to achieve both phase and amplitude modulation, then modulation capability is improved, but device complexity increases
Solution Approach 1:
The patent merges the phase modulation and amplitude modulation control into a single unified digital structure. Both modulation types are achieved by selecting different lookup tables (one for phase, one for amplitude) and combining their outputs through digital signal processing, eliminating the need for separate complex control signal paths and reducing overall device complexity.
Solution Approach 2:
The patent creates a universal modulation device that can generate both phase and amplitude modulation using a single numerically controlled oscillator and lookup table structure. The same hardware framework supports multiple modulation schemes by simply changing the lookup table contents, providing multi-functionality without increasing structural complexity.
3Adaptability or versatility
If multiple ILOs with different control signals are used to generate complex modulations, then modulation diversity is improved, but power consumption increases
Solution Approach 1:
The patent combines multiple modulation functions into a single oscillator system rather than using multiple separate oscillators. The numerically controlled oscillator generates both phase and amplitude modulated signals by processing a single input signal through different lookup tables, reducing the total number of active components and thereby lowering power consumption while maintaining modulation diversity.
4Adaptability or versatility
If internal ILO structure is modified to generate amplitude modulation, then amplitude control is achieved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent replaces the need to modify the internal analog structure of oscillators with a digital signal processing approach. Amplitude modulation is achieved by looking up amplitude values in a digital table and combining them with phase information through digital multiplication and addition, eliminating the need for complex analog amplitude control circuits and simplifying manufacturing.
Data Source
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AI summary
Amplitude modulation device (100), comprising: - TORP generators, - a multi-bit thermometric code generator (102) encoding an amplitude modulation, - a control circuit (108) for the TORP generators, applying or not, to the control input of the power supply of the TORP generators, the periodic signal of frequency FPRP as a function of the bits of the thermometric code signal, and - a processing circuit (118) coupled to the outputs of the TORP generators, and configured to perform a linear combination of signals delivered by the TORP generators.