RF Port and Shield Layout for Lower Substrate Noise

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Solution Overview

Problem

Conventional RF device fabrication often results in abnormal gain and frequency relationships due to fabrication parameters, leading to noise issues in the substrate.

Innovation Solution

The RF device design includes a main device positioned centrally on a substrate with strategically adjusted lengths of bar patterns and increased metal pattern coverage to improve substrate noise and gain-frequency relationships, utilizing a configuration where the lengths of the bar patterns are within 30% difference from the main device's diffusion region lengths and enhancing metal pattern coverage to 50% or above.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional fabrication parameters are used, then manufacturing process is simple, but gain and frequency relationship becomes abnormal and substrate noise increases

Engineering Contradiction:
Improvegain and frequency relationshipVSAvoidsubstrate noise
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent introduces bar patterns as intermediary structures between the main device and substrate. These bar patterns act as a mediator to improve the gain and frequency relationship while reducing substrate noise. The bar patterns are strategically designed with specific dimensions (length within 30% of main device diffusion region) and positioning to achieve this mediating effect, serving as a buffer zone that prevents direct noise coupling while maintaining electrical performance.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent applies parameter changes by optimizing the dimensions and configuration of metal patterns and bar patterns. Specifically, the bar pattern length is set within 30% of the main device diffusion region length, and metal pattern coverage is increased to 50% or above. These parameter adjustments directly address the abnormal gain and frequency relationship while minimizing substrate noise generation.

Inventive Principle:
Principle #35Parameter changes

2Object-generated harmful factors

If metal pattern coverage is increased to 50% or above, then substrate noise is reduced, but manufacturing complexity increases

Engineering Contradiction:
Improvesubstrate noiseVSAvoidfabrication process
Core Design Contradiction:
Object-generated harmful factorsVSEase of manufacture

Solution Approach 1:

The patent segments the metal pattern coverage into distinct regions: bar patterns positioned between the main device and substrate, and additional metal patterns covering 50% or above of the substrate area. This segmentation allows the noise reduction function to be achieved through distributed metal structures rather than a single complex pattern, simplifying the fabrication process while maintaining effectiveness in reducing substrate noise.

Inventive Principle:
Principle #1Segmentation

3Reliability

If bar pattern length is optimized to within 30% difference from main device diffusion region, then gain and frequency relationship improves, but device area increases

Engineering Contradiction:
Improvegain and frequency relationshipVSAvoiddevice area
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The patent optimizes the bar pattern length parameter to be within 30% of the main device diffusion region length. This specific parameter range achieves the best compromise between improving gain and frequency relationship while minimizing the additional device area required. The constrained parameter range ensures that the noise reduction benefits are achieved without excessive area expansion.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4404257A1Radio frequency device
Publication Date: 2024.07.24 UNITED MICROELECTRONICS CORP
  • EP4404257A1 patent drawingFigure 1
  • EP4404257A1 patent drawingFigure 2
  • EP4404257A1 patent drawing

AI summary

A radio-frequency (RF) device includes a main device on a substrate, a first port extending along a first direction adjacent to a first side of the main device, a second port extending along the first direction adjacent to a second side of the main device, a first shield structure adjacent to a third side of the main device, a second shield structure adjacent to a fourth side of the main device, a first connecting structure extending along a second direction to connect the first port and the main device, and a second connecting structure extending along the second direction to connect the second port and the main device.