Backward Wave Nonlinear Transmission Line for Electron Beam Modulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional nonlinear transmission line (NLTL) modulated beam drivers operate in forward wave configurations, where the electromagnetic drive pulse and RF oscillations travel in the same direction, limiting RF pulse length and amplitude consistency, which affects the efficiency and uniformity of electron beam modulation in high power microwave devices.
Innovation Solution
A backward wave NLTL configuration is introduced, where the RF oscillations travel in the opposite direction of the electromagnetic pulse, generated by forming a shock front within the NLTL, and combined with the input pulse to modulate an electron beam, using a termination component to ground the electromagnetic pulse and prevent interference, enhancing RF pulse length and amplitude consistency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If a forward wave NLTL configuration is used, then the device structure is simpler, but the RF pulse length is limited and amplitude consistency is poor
Solution Approach 1:
The patent inverts the conventional forward wave NLTL configuration by implementing a backward wave configuration where the RF oscillations travel in the opposite direction of the electromagnetic pulse. This inversion allows the RF pulse to be generated and sustained along the entire length of the NLTL, significantly extending the RF pulse length while maintaining amplitude consistency through the reversed propagation direction.
2Manufacturing precision
If a forward wave NLTL configuration is used, then the electromagnetic pulse can directly drive the electron beam, but the amplitude consistency of RF oscillations is poor
Solution Approach 1:
By inverting the wave propagation direction in the NLTL, the RF oscillations travel opposite to the electromagnetic pulse. This backward wave configuration creates a standing wave pattern that provides consistent amplitude along the interaction region, thereby improving electron beam modulation uniformity while maintaining operational simplicity through direct electron beam driving.
3Productivity
If the electromagnetic pulse travels in the same direction as RF oscillations, then the device structure is simpler, but the electron beam modulation efficiency is reduced
Solution Approach 1:
The patent inverts the conventional configuration by having RF oscillations travel in the opposite direction to the electromagnetic pulse. This backward wave arrangement increases the interaction time and overlap between the RF field and electron beam, significantly improving modulation efficiency. The configuration maintains simplicity by using the same basic NLTL structure without additional complex components.
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
The backward wave NLTL configuration generates a substantially longer RF pulse with greater amplitude consistency compared to forward wave devices, leading to improved uniformity and efficiency in electron beam modulation, allowing for a smaller system with enhanced performance.
Implementation Method 1
the shock front 3, which is formed at the leading edge of the input current pulse 4, propagates down the length of the NLTL at velocity us and RF oscillations 5 are generated
Implementation Method 2
the nonlinear inductor 62d, typically a ferrite, is driven fully into saturation. Fully saturated inductors 63 no longer exhibit significant nonlinearity
Implementation Method 3
using a termination component to ground the electromagnetic pulse and prevent interference
Implementation Method 4
receive a combined electromagnetic pulse from the RF filter and the backward wave RF oscillation from the NLTL to cause excitation of a modulated voltage between the anode and cathode, and to cause the electron beam generating device to emit an electron beam that is modulated at the predetermined frequency
Implementation Method 5
excitation of a modulated voltage between the anode and cathode
Data Source
AI summary
An apparatus, system, and method for performing electron beam modulation includes an input pulser to provide an electromagnetic pulse; a radio frequency (RF) filter to filter the electromagnetic pulse; a nonlinear transmission line to receive the electromagnetic pulse, and generate a backward wave RF oscillation of a predetermined frequency to travel in a direction opposite that of the electromagnetic pulse; and an electron beam generating device including an anode and a cathode, the electron beam generating device to receive a combined electromagnetic pulse from the RF filter and the backward wave RF oscillation from the nonlinear transmission line to cause excitation of a modulated voltage between the anode and cathode, and to cause the electron beam generating device to emit an electron beam that is modulated at the predetermined frequency of the backward wave RF oscillation.