Phased Array Amplitude Modulation Using Selective Amplifier Switching
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Solution Overview
Problem
Current digital communication systems face inefficiencies in power and modulation, where either efficient modulation or amplification is achieved but not both, particularly in phased array systems, which also lack resistance to interception.
Innovation Solution
The array amplitude modulation (AAM) system maps data symbols to both phase and amplitude modulation signals, using nonlinear amplifiers and a control circuit to selectively enable/disable antenna element amplifiers, producing a phase and amplitude modulated transmission, thereby increasing power efficiency and resistance to interception.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If QAM modulation is used to achieve efficient modulation, then modulation efficiency is improved, but amplifier efficiency deteriorates due to requirement for linear amplifiers
Solution Approach 1:
The invention segments the modulation function into two independent parts: phase modulation applied to all antenna elements, and amplitude modulation achieved by selectively enabling/disabling individual antenna elements. This segmentation allows each antenna element to operate with efficient non-linear amplifiers while the overall system achieves QAM-like modulation through coordinated phase and amplitude control across the array.
Solution Approach 2:
The invention transitions from single-antenna amplitude modulation to multi-antenna array amplitude modulation, adding the spatial dimension to the modulation process. By controlling which antenna elements are active in the array, amplitude modulation is achieved without requiring linear amplifiers, thus resolving the contradiction between modulation efficiency and amplifier efficiency.
2Loss of energy
If PSK modulation is used to allow efficient non-linear amplification, then amplifier efficiency is improved, but modulation efficiency deteriorates
Solution Approach 1:
The invention merges phase shift keying (PSK) with amplitude modulation by combining phase modulation signals applied to all antenna elements with amplitude modulation achieved through selective element activation. This merging creates a hybrid modulation scheme that achieves both efficient non-linear amplification and high modulation efficiency, effectively combining the advantages of both PSK and QAM.
3Loss of energy
If more antenna elements are used to improve power and efficiency, then power efficiency is improved, but device size and weight increase
Solution Approach 1:
The invention employs periodic activation patterns of antenna elements, where elements are enabled and disabled in systematic patterns (such as alternating or sequential patterns) to achieve amplitude modulation. This periodic action allows the system to use fewer physical antenna elements compared to continuous operation systems, reducing overall equipment size and weight while maintaining power efficiency through the modulation of active element patterns.
4Reliability
If conventional modulation systems are used to achieve reliable communication, then communication reliability is improved, but resistance to interception deteriorates
Solution Approach 1:
The invention implements dynamic control of antenna element activation patterns, where the set of active elements changes over time according to the modulation signal. This dynamic behavior creates a time-varying radiation pattern that is more difficult to intercept and analyze compared to static antenna systems, thereby improving resistance to interception while maintaining communication reliability through the structured modulation scheme.
Data Source
AI summary
Array amplitude modulation which includes mapping a data symbol to a phase modulation signal and an amplitude modulation signal for transmission from antenna elements; applying the phase modulation signal to the antenna element amplifiers; and generating a pattern of enabling/disabling the antenna element amplifiers as a function of the amplitude modulation to produce a phase and amplitude modulated transmission from the antenna elements.