ESD-Protected Phase Shifter for Phased Array Stability

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Solution Overview

Problem

Existing phase shifters in phased arrays face challenges with stability, signal integrity, and manufacturing complexity, particularly due to sensitivity to temperature variations and manufacturing tolerances, and they often require extensive calibration.

Innovation Solution

A phase shifter design utilizing ESD protection circuits with switchable two-port devices and delay lines to provide adjustable phase shifts, leveraging the ESD protection circuit's ability to non-destructively discharge high voltages and currents, thereby reducing switching losses and manufacturing complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If continuously tuneable phase shifters are used to provide arbitrary phase shift, then phase adjustment flexibility is improved, but sensitivity to temperature variations and manufacturing tolerances increases

Engineering Contradiction:
Improvephase adjustment flexibilityVSAvoidsensitivity to temperature variations
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The phase shifter is divided into multiple discrete sections (e.g., 4 sections providing 0°, 90°, 180°, 270° phase shifts). Each section is independently controllable through switching devices, allowing the system to achieve discrete phase adjustment without the continuous tuning sensitivity issues. The segmentation transforms a continuously sensitive system into discrete, stable steps.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The phase shifter uses dynamically switchable transmission lines where switching devices (PIN diodes or transistors) can rapidly change the active transmission path. This dynamic switching capability provides flexible phase control while maintaining stability, as each switched path is designed to be environmentally stable rather than continuously adjustable.

Inventive Principle:
Principle #15Dynamics

2Reliability

If discrete tuneable phase shifters are used to reduce sensitivity to environmental variations, then reliability is improved, but beam forming capabilities are restricted

Engineering Contradiction:
Improvesensitivity to environmental variationsVSAvoidbeam forming capabilities
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The phase shifter employs multiple discrete phase shift sections (e.g., four sections with 0°, 90°, 180°, 270° shifts) that can be independently selected. This segmentation provides sufficient discrete steps for effective beam forming in phased arrays while maintaining the stability of discrete design. The multiple segments enable practical beam steering capabilities without requiring continuous adjustment.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The phase shifter design serves multiple functions: it provides discrete phase control for beam forming, maintains environmental stability, and offers sufficient resolution for practical applications. The universal design accommodates various beam forming requirements through combinatorial switching of the discrete sections, making it versatile enough for most phased array applications.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Measurement precision

If switched-line phase shifters with multiple sections are used to achieve desired phase shift resolution, then phase control precision is improved, but device complexity increases

Engineering Contradiction:
Improvephase control resolutionVSAvoidnumber of switching devices
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The phase shifter is segmented into N independent sections, each with its own switching device. This segmentation achieves fine phase control resolution (360°/2^N) by combining the effects of multiple binary choices, rather than requiring a single complex continuous adjustment mechanism. The modular segmented structure makes the complexity manageable and scalable.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The phase shift is achieved by changing the electrical parameters (impedance states) of the switching devices rather than mechanically adjusting transmission line lengths. This parameter change approach allows digital-like control of phase shift through voltage-controlled switching, simplifying the control mechanism while maintaining precise phase resolution through the combinatorial effect of multiple binary switches.

Inventive Principle:
Principle #35Parameter changes

4Ease of operation

If conventional switching devices are used in phase shifters, then phase shifting functionality is achieved, but switching losses increase

Engineering Contradiction:
Improvephase shifting functionalityVSAvoidswitching losses
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The patent replaces mechanical or conventional high-loss switching mechanisms with ESD protection circuits that utilize avalanche breakdown for switching. This substitution eliminates the need for traditional switching devices that generate significant switching losses, as the ESD circuits are specifically designed to handle high voltages and currents with minimal energy dissipation during the switching transition.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The ESD protection circuits operate by changing their impedance state through controlled avalanche breakdown. By utilizing the nonlinear I-V characteristics of the ESD diodes, the system achieves low-loss switching between high-impedance (signal blocked) and low-impedance (signal passed) states. The parameter change from linear to nonlinear operation enables efficient switching with reduced energy losses.

Inventive Principle:
Principle #35Parameter changes

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 improved stability, reduced switching losses, and simplified manufacturing, with enhanced signal integrity and reduced calibration efforts, making it suitable for high-frequency applications.

Implementation Method 1

ESD protection circuits, which typically utilize the switching capabilities of a plurality of two-port devices

Methodology Applied
Scientific EffectElectrostatic Discharge: Electrostatic Discharge

Implementation Method 2

a first delay line configured to provide a first phase shift to a signal transmitted from the signal input to the signal output via the first signal path

Methodology Applied
Scientific EffectElectromagnetic Propagation: Electromagnetic Induction

Data Source

PatentEP3275041B1Phase shifter
Publication Date: 2019.01.30 FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV
  • EP3275041B1 patent drawingFigure 1
  • EP3275041B1 patent drawingFigure 2
  • EP3275041B1 patent drawingFigure 3

AI summary

Embodiments provide a phase shifter comprising a signal input, a signal output, an ESD protection circuit, a first signal path between the signal input and the signal output and a second signal path between the signal input and the signal output. The ESD protection circuit comprises a first two port device and a second two port device, each two port device being switchable between a high impedance state and a low impedance state. The first signal path comprises the first two port device of the ESD protection circuit and a first delay line configured to provide a first phase shift to a signal transmitted from the signal input to the signal output via the first signal path. The second signal path comprises the second two port device of the ESD protection circuit and a second delay line configured to provide a second phase shift, different from the first phase shift, to the signal transmitted from the signal input to the signal output via the second signal path.