Bidirectional RTPS Circuit for Gain-Invariant 360° Phase Shifting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Reflection type phase shifters (RTPS) used in beamforming introduce undesirable gain variation with phase shift, degrading performance in applications like beamforming gain and sidelobe suppression.
Innovation Solution
A gain invariant bidirectional phase shifter is developed, incorporating a differential quadrature hybrid coupler, a switch network, and a differential reflection type phase shifter (RTPS), which provides 360° of phase shift with low attenuation variation (<0.4 dB) using a quadrant select circuit and variable resistors to control phase and gain.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a reflection type phase shifter (RTPS) is used to provide phase shifting capability, then phase shift range is improved, but gain variation increases
Solution Approach 1:
The phase shifter is divided into multiple quadrants (first quadrant circuit, second quadrant circuit, third quadrant circuit, fourth quadrant circuit), each handling a 90-degree phase shift range. The quadrant select circuit selects which quadrant is active based on the desired total phase shift (0-360 degrees). This segmentation allows each segment to maintain consistent gain characteristics while the overall system achieves full 360-degree phase control with minimal gain variation (<0.4 dB).
Solution Approach 2:
The invention uses variable resistors (first variable resistor, second variable resistor, third variable resistor, fourth variable resistor) within each quadrant circuit to dynamically adjust impedance and control the phase shift amount. The quadrant select circuit dynamically switches between different quadrant configurations based on the required phase shift. This dynamic adjustment mechanism enables continuous phase control while maintaining stable gain across the entire 360-degree range.
2Device complexity
If bidirectional operation is implemented to share circuitry between transmit and receive modes, then device complexity is reduced, but phase control precision may deteriorate
Solution Approach 1:
The bidirectional phase shifter is designed to operate in both transmit and receive modes using the same hardware circuitry. The first pair of I/O ports and second pair of I/O ports can function as input or output depending on the operational mode. The quadrant select circuit and variable resistors are configured to provide consistent phase control characteristics in both directions, ensuring that phase control precision is maintained despite the shared circuitry architecture.
3Reliability
If quadrant select circuit with variable resistors is used to achieve 360° phase shift with low attenuation variation, then gain stability is improved, but device complexity increases
Solution Approach 1:
Each quadrant circuit (first, second, third, fourth quadrant circuits) is designed with specific local characteristics optimized for its 90-degree phase range. Each quadrant contains tailored variable resistors and impedance elements configured for its specific operational range. This local optimization ensures that each quadrant maintains consistent gain characteristics, and when combined through the quadrant select circuit, the overall system achieves 360-degree phase control with minimal gain variation while managing complexity through modular design.
Data Source
AI summary
A bidirectional phase shifter includes a differential quadrature hybrid coupler, a switch network, and a differential reflection type phase shifter (RTPS). The differential quadrature hybrid coupler includes a first phase input/output (I/O) port, an inverse first phase I/O port, a second phase I/O port, and an inverse second phase I/O port. The switch network is coupled to the first phase I/O port, the inverse first phase I/O port, the second phase I/O port, and the inverse second phase I/O port. The differential RTPS including a differential I/O port coupled to the switch network.