QAM Waveform Transmission Using Multiple Saturation Amplifiers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
It is challenging to amplify signals to sufficiently high power for mm-wave communications, particularly at frequencies between 70 GHz and 120 GHz, as typical solid-state amplifiers struggle to operate in their linear regime, limiting the transmission distance to only a few kilometers.
Innovation Solution
A system utilizing multiple mixers and amplifiers to combine synchronized phase-shift keying signals with a common local oscillator, powering multiple radiators in discrete states, which radiate through far-field electromagnetic propagation to effectively mimic transmission from a single amplifier, allowing for higher power output and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a single solid state amplifier is used to amplify mm-wave signals, then the transmission distance can be extended, but the amplifier cannot operate in its linear regime and sufficient power cannot be achieved
Solution Approach 1:
The single amplifier function is segmented into multiple amplifiers (at least two), each operating in saturation mode. These amplifiers process different portions of the modulated signal and combine their outputs to achieve the equivalent of a high-power linear amplifier, resolving the contradiction between power output and linear operation capability.
2Power
If multiple amplifiers are used to achieve higher power output, then the transmission distance increases, but the device complexity increases
Solution Approach 1:
The system uses dynamic signal processing where the modulated signal is split and processed by multiple amplifiers with different delay times. The delays and signal routing are dynamically adjusted to ensure coherent combining at the output, achieving high power output while managing complexity through structured dynamic control.
Solution Approach 2:
Multiple amplifier outputs are merged/combined at the output stage to produce the final high-power signal. This combining process integrates the outputs of individual saturation-mode amplifiers to achieve the equivalent performance of a single high-power linear amplifier, reducing the overall system complexity.
3Use of energy by moving object
If amplifiers are driven into saturation for higher efficiency, then power output increases, but signal linearity deteriorates
Solution Approach 1:
The signal is pre-processed by splitting it into multiple paths with different delay times before amplification. This preliminary arrangement allows each amplifier to work in saturation mode while the overall signal linearity is preserved through the coherent combining of delayed signal portions at the output.
Solution Approach 2:
The system changes the operational parameters of the amplifiers from linear mode to saturation mode, achieving higher efficiency. The parameter changes extend to the signal processing approach, using multiple delay times and coherent combining to maintain signal quality despite the non-linear operation of individual amplifiers.
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 approach enables the production of more output power and greater efficiency by driving amplifiers into saturation rather than the linear region, overcoming the limitations of single amplifiers and achieving longer transmission distances with reduced interaction and complexity.
Implementation Method 1
wherein the radiated states from the first, second, third, fourth, fifth, sixth, and seventh radiators combine through far-field electromagnetic propagation and effectively sum at the receiver
Data Source
Figure 1
Figure 2
AI summary
An encoder can convert a stream of data into three or four synchronized 4-PSK signals, for 64-QAM and 256-QAM, respectively. Three or four mixers can combine the three or four synchronized PSK signals with a common local oscillator signal to form three or four respective amplifiable signals, which can all have the same amplitude. One amplifier receives a first of the amplifiable signals and powers one radiator. Two amplifiers both receive a second of amplifiable signals and power two respective radiators. Four amplifiers receive a third of the amplifiable signals and power four respective radiators. The amplifiers can all operate in near or full saturation. Each radiator radiates in one of a plurality of discrete, specified states. The radiated states from the radiators combine through far-field electromagnetic propagation and effectively sum at the receiver to mimic transmission from a single amplifier.