Digital Reactance Circuit for Wide-Range RF Phase Shifting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing variable reactance elements in microwave circuits, such as phase shifters, face limitations in frequency range and complexity of control signals due to reliance on either variable capacitors or inductors, which restrict the range of phase shift and impedance matching.
Innovation Solution
A digital variable reactance element comprising a combination of digital capacitors and inductors connected in series or parallel, with switchable digital switches, allowing for wide-range reactance variation by switching between on and off states, thereby simplifying control signals and enhancing phase shift and impedance matching capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If only variable capacitors or variable inductors are used, then the device structure is simple, but the reactance variation range is limited
Solution Approach 1:
The patent combines variable capacitors and variable inductors into a single integrated variable reactance element. The digital switch selectively connects either the capacitor or inductor to the signal path, allowing the device to provide both capacitive and inductive reactance variations within one unified structure, thereby expanding the reactance variation range without proportionally increasing device complexity.
Solution Approach 2:
The variable reactance element achieves multi-functionality by incorporating both capacitive and inductive components that can be selectively activated. The digital switch enables the same physical structure to perform different functions (capacitive reactance adjustment or inductive reactance adjustment) based on control signals, making the device universally applicable for wide-range reactance control.
2Adaptability or versatility
If multiple variable capacitors or inductors are used to expand reactance range, then the reactance variation range increases, but the control signal complexity increases
Solution Approach 1:
Multiple variable reactance components (capacitors and inductors) are merged into a single integrated element with unified control. Instead of requiring separate control signals for each component, the digital switch provides centralized control that selectively activates the appropriate component based on the desired reactance state, thereby reducing control signal complexity while maintaining expanded reactance variation range.
3Speed
If frequency increases, then the operating frequency range expands, but the phase shift range reduces and loss increases
Solution Approach 1:
The patent changes the reactance parameter dynamically by selectively switching between capacitive and inductive modes. At higher frequencies where conventional capacitive phase shifters lose effectiveness, the digital switch can activate the inductive component which maintains better phase shift characteristics, thereby preserving phase shift range and reducing loss across an expanded frequency spectrum.
Data Source
AI summary
A digital variable reactance element includes digital capacitors and digital inductors connected in series or in parallel. Each of the digital capacitors includes a capacitor and a first digital switch connected in series or in parallel. The first digital switch is switchable between on and off states. Each of the digital inductors includes an inductor and a second digital switch connected in series or in parallel. The second digital switch is switchable between on and off states.