Multi-Row Digital Phase Shifter Layout for Interference Suppression
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Solution Overview
Problem
Digital phase shift circuits in multi-row structures experience mutual interference due to inter-row connections, which affect their performance in phased array antennas.
Innovation Solution
A digital phase shifter design with a multi-row structure that includes a ground pattern connecting neighboring ground conductors and outer lines, along with capacitors and electronic switches, to minimize interference between adjacent rows.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If digital phase shift circuits are disposed in a multi-row structure to save mounting space, then the area utilization is improved, but mutual interference between neighboring rows occurs
Solution Approach 1:
A ground pattern is introduced as an intermediary element between neighboring digital phase shift circuits in adjacent rows. This ground pattern acts as a shielding mediator that redirects return currents, preventing them from coupling between adjacent signal lines in neighboring rows, thereby reducing mutual interference while maintaining the compact multi-row layout
Solution Approach 2:
The solution extends the problem-solving approach from the horizontal plane to the vertical dimension by utilizing multiple conductor layers. The ground pattern is positioned in a different layer (second conductor layer) than the signal lines (first conductor layer), creating a three-dimensional arrangement that provides interference suppression without increasing the footprint area
2Reliability
If ground conductors and outer lines are connected to form integrated ground patterns, then the ground reference is improved, but interference between adjacent circuits increases
Solution Approach 1:
The ground pattern is designed with local quality variations, being positioned specifically between certain signal lines (e.g., between outer lines or between inner and outer lines) rather than uniformly across all positions. This selective placement provides ground reference stability where needed while minimizing interference in other regions
Solution Approach 2:
The ground pattern, which could potentially create additional interference paths, is instead designed to convert harmful return current paths into beneficial shielded paths. By providing a controlled low-impedance ground reference, it actually reduces overall interference compared to uncontrolled return current paths
Data Source
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AI summary
A digital phase shifter of the present invention is a digital phase shifter in which digital phase shift circuits are cascade-connected, each of the digital phase shift circuits including a signal line, a pair of inner lines provided on both sides of the signal line, a pair of outer lines provided on outer sides of the inner lines, a first ground conductor connected to one ends of the inner lines and one ends of the outer lines, a second ground conductor connected to the other ends of the outer lines, and a pair of electronic switches provided between the other ends of the inner lines and the second ground conductors. The digital phase shift circuits include a multi-row structure constituted by a front row and a rear row, and an inter-row connection structure in which the outer line in the front row and the outer line in the rear row are connected, and the number of the digital phase shift circuits from an input end of an uppermost side digital phase shift circuit in the front row to an input end of an uppermost side digital phase shift circuit in the rear row is set such that a phase of a signal input to the front row uppermost side digital phase shift circuit and a phase of a signal input to the rear row uppermost side digital phase shift circuit are anti-phase with each other.