Spiral Digital Phase Shifter Layout for Compact Phase Control
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Solution Overview
Problem
The configuration of digital phase shifters with cascaded digital phase shift circuits tends to increase in length, and bending these circuits can lead to increased areas where magnetic fields generated in outer lines weaken each other, affecting phase shift operation.
Innovation Solution
A digital phase shifter with a spiral configuration using bend-type connection units between digital phase shift circuits, where each circuit includes inner and outer lines, ground conductors, and electronic switches, with transmission lines formed on different layers and connected via ground layers through via-holes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an analog phase shifter is used to control phase, then phase control is continuous, but the amplitude response is not flat and insertion loss varies with phase setting
Solution Approach 1:
The phase shifter is divided into multiple independently controllable phase shifter elements (first, second, third elements), each contributing a discrete phase shift. By segmenting the phase control into multiple digital steps rather than continuous analog adjustment, the system achieves both discrete phase control and maintained amplitude response characteristics.
Solution Approach 2:
Multiple phase shifter elements are combined in parallel configurations where their output signals are summed. The first and second elements are combined in one parallel path, while the third element is combined in another parallel path. This merging approach allows the system to achieve the desired phase shift while maintaining a flat amplitude response through constructive interference of the combined signals.
2Adaptability or versatility
If an analog phase shifter is used, then phase adjustment is possible, but spurious signals are generated due to impedance mismatch
Solution Approach 1:
The phase shifter transitions from static analog control to dynamic digital control where each phase shifter element can be independently switched on or off based on digital control signals. This dynamic switching allows precise phase adjustment while maintaining consistent impedance characteristics, thereby reducing spurious signal generation.
3Reliability
If digital signal processing is applied to correct amplitude response, then amplitude flatness can be improved, but the system complexity increases
Solution Approach 1:
The phase shifter system inherently maintains amplitude response flatness through its parallel element configuration and signal combining approach. The structure itself provides the amplitude correction function without requiring external digital signal processing, thereby avoiding increased system complexity while achieving the desired amplitude characteristics.
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
This configuration reduces the number of areas where magnetic fields weaken each other, resulting in a compact digital phase shifter design.
Implementation Method 1
a first phase shifter element introduces a first phase shift to a signal, a second phase shifter element introduces a second phase shift to the signal, and a third phase shifter element introduces a third phase shift to the signal
Data Source
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AI summary
A digital phase shifter includes a plurality of digital phase shift circuits connected in cascade and one or more bend-type connection units each configured to make a connection between two digital phase shift circuits of the plurality of digital phase shift circuits. Each of the digital phase shift circuits includes at least a signal line, a pair of inner lines provided at both sides of the signal line, a pair of outer lines provided outside of the inner lines, a first ground conductor connected to one ends of the inner lines and 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 conductor. Each of the digital phase shift circuits is a circuit set in a low-delay mode in which a return current flows through the inner line or a high-delay mode in which a return current flows through the outer line. The plurality of digital phase shift circuits connected in cascade are arranged in a spiral shape via the connection units.