Differential Transmission Line Phase Shifter for Stable RF Phase Control
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Solution Overview
Problem
Existing RF circuits in wireless communication and radar sensors face challenges in phase-shifting accuracy, precision, calibration complexity, and bandwidth, particularly with IQ phase shifters that are unstable under pressure voltage temperature changes and require single-point calibration.
Innovation Solution
A transmission line phase shifter with differential transmission lines and phase adjusting circuits that adjust equivalent inductance and capacitance to achieve stable phase shifting, using switch tubes and capacitors to control phase states, and a cascaded circuit design for enhanced phase control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If IQ phase shifter is used to achieve phase control capability, then phase shifting function is provided, but phase-shifting accuracy and stability deteriorate under pressure voltage temperature changes
Solution Approach 1:
The patent employs switch tubes to dynamically switch between different transmission line configurations, enabling the phase shifter to adapt to different phase requirements while maintaining stability. The dynamic switching mechanism allows the system to change its electrical characteristics without mechanical movement, improving reliability under environmental variations.
Solution Approach 2:
The invention changes the electrical parameters (inductance and capacitance) of the transmission lines by switching between different circuit configurations. This parameter change approach enables precise phase control while maintaining stability, as the changes are achieved through electronic switching rather than mechanical adjustment, reducing sensitivity to pressure, voltage, and temperature variations.
2Adaptability or versatility
If IQ phase shifter is used to provide phase control, then phase shifting is achieved, but calibration complexity increases and single-point calibration is required
Solution Approach 1:
The phase shifter is divided into multiple independent phase-shifting units, each capable of providing a specific phase shift (e.g., 0° or 180°). This segmentation allows the overall phase control to be achieved by combining multiple simple units, reducing the calibration complexity compared to a single complex IQ phase shifter that requires single-point calibration.
Solution Approach 2:
Instead of using a single phase shifter that provides continuous phase control requiring precise calibration, the invention uses multiple phase-shifting units that provide discrete phase shifts. This partial action approach (using only specific phase states) simplifies the calibration process, as each unit can be calibrated independently to fixed points rather than requiring continuous calibration across the entire phase range.
3Adaptability or versatility
If transmission line length is increased to achieve phase shifting, then phase control range is improved, but frequency bandwidth deteriorates
Solution Approach 1:
The invention changes the electrical parameters (inductance and capacitance) of the transmission lines through circuit configuration switching rather than relying solely on physical length changes. This allows phase control to be achieved while maintaining a compact transmission line structure, thereby preserving the frequency bandwidth. The parameter changes are achieved through switch tubes that reconfigure the electrical characteristics of the transmission paths.
4Device complexity
If phase shifter design is simplified to reduce calibration complexity, then calibration process is improved, but phase-shifting precision deteriorates
Solution Approach 1:
The phase shifter is segmented into multiple independent units, each with simple calibration requirements. This segmentation reduces the overall calibration complexity while maintaining precision, as the cumulative effect of multiple precisely-controlled simple units achieves the desired phase accuracy without requiring complex single-point calibration of a single unit.
Solution Approach 2:
The invention uses a composite structure combining multiple phase-shifting units with different characteristics. This composite approach allows the system to achieve high phase-shifting precision through the combination of simpler units, each contributing to the overall accuracy while having reduced individual calibration complexity.
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 solution provides stable and precise phase shifting with reduced calibration complexity, maintaining impedance matching and improving the efficiency and accuracy of RF signal processing in wireless communication and radar sensors.
Implementation Method 1
the phase adjusting circuit is configured to receive at least one phase shifting control signal and to adjust electrical parameters of a transmission path according to the at least one phase shifting control signal, so that the output RF signal has a phase shift of a first phase or a second phase relative to the input RF signal
Implementation Method 2
A respective transmission line phase-shifting unit of the at least one transmission line phase-shifting unit comprises a first pair of differential transmission lines, a second pair of differential transmission lines
Data Source
AI summary
A transmission line phase shifter, a system, a chip, and a radar sensor are provided. The transmission line phase shifter includes at least one transmission line phase-shifting unit. A respective transmission line phase-shifting unit includes a first pair of differential transmission lines, a second pair of differential transmission lines, and a phase adjusting circuit. The phase adjusting circuit is configured to adjust electrical parameters of a transmission path where at least one pair of transmission lines of the first pair of differential transmission lines and the second pair of differential transmission lines is located according to at least one phase shifting control signal received, so as to enable that a RF signal output from the respective transmission line phase-shifting unit has a phase shift of a first phase or a second phase relative to an input RF signal of the respective transmission line phase-shifting unit.