Multi-Phase Digital Drive Generation for Harmonic-Suppressed Amplifiers
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Solution Overview
Problem
Existing phase drive generators require complex analog circuitry with many components and hand tuning, leading to inefficiencies in harmonic suppression and output power, particularly due to the need for multiple phase drives and amplifiers to achieve desired harmonic cancellation.
Innovation Solution
A system and method for digitally producing amplifier drive signals using multiple phase-shifted signals, where the drive signal is a three-level signal (‘1’, ‘0’, and ‘−1’) to direct amplifiers, allowing for independent pulse generation and combination to produce a stair-step approximation of the desired transmit signal, reducing harmonic content through digital logic and direct digital synthesis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If analog circuitry is used to create phase drive signals, then harmonic suppression can be achieved, but the system requires a large number of components and hand tuning
Solution Approach 1:
The patent replaces the mechanical/analog circuitry system with a digital signal processing system. Instead of using analog components and hand tuning to create phase drive signals, the invention uses digital logic and direct digital synthesis to generate the same signals, thereby eliminating the complexity of analog circuitry while maintaining harmonic suppression capabilities
Solution Approach 2:
The patent changes the fundamental parameter of signal generation from analog voltage manipulation to digital pulse generation. By using three-level digital signals (high, zero, low) instead of continuous analog waveforms, the system achieves the same phase drive functionality with simplified digital circuitry, reducing component count and eliminating hand tuning requirements
2Object-generated harmful factors
If multiple phase drives and amplifiers are used to achieve desired harmonic cancellation, then harmonic suppression is improved, but the system complexity and component count increase
Solution Approach 1:
The patent merges the functions of multiple phase drives and amplifiers into a single integrated digital signal generation system. By using direct digital synthesis to create the phase drive signals, the system achieves harmonic cancellation through digital signal processing rather than through multiple separate analog amplifier stages, thereby reducing overall system complexity
Solution Approach 2:
The patent creates a universal digital signal generation system that can produce multiple phase drive signals with different phase relationships from a single digital logic unit. This multi-functional approach replaces the need for multiple dedicated analog circuitry blocks, achieving the same harmonic suppression with fewer components
3Object-generated harmful factors
If symmetric waveforms with 120° pulse width are used, then odd harmonics of 5th harmonic and above are suppressed, but the system requires precise waveform symmetry control
Solution Approach 1:
The patent replaces the mechanical precision requirement for waveform symmetry with digital precision. Instead of relying on precise analog circuit timing and symmetry, the invention uses digital logic to generate exactly symmetric waveforms through programmed pulse widths and phase relationships, eliminating the need for manual adjustment and precision manufacturing tolerances
Solution Approach 2:
The patent pre-calculates and pre-programs the optimal pulse widths and phase relationships in the digital logic design to achieve the desired 120° symmetric waveform. This preliminary digital configuration ensures exact symmetry without requiring real-time adjustment or precision manufacturing, as the symmetry is built into the digital signal generation logic itself
Data Source
AI summary
A system for producing a for digitally producing amplifier drive signals for high power transmission includes signal generators to produce, based on the desired transmit frequency and modulation, a high digital pulse, low digital pulse, or no digital pulse of the desired pulse width and phase relationship. The drive signal is a three-level signal, having states of “1”, “0”, and “−1”. A drive signal will direct the amplifier to output either its high voltage rail, 0 volts, or its low voltage rail. Multiple signal sets may be used to independently generate pulses based on differently phase shifted signals. These multiple drive signals can be used to drive multiple amplifiers, whose combined output produces a stair-step approximation to the desired transmit signal.