Filter Circuit Ground-Side Connection for Parasitic Inductance Reduction
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Solution Overview
Problem
Existing electrical modules with filter circuits, such as duplexers, are affected by additional module components that shift the zero points in the transmission function, leading to interference and reduced performance.
Innovation Solution
The electrical module incorporates a filter circuit with shunt arms connected to ground, where the ground-side connection of these arms is made outside the chip and second substrate, using a common ground surface to reduce parasitic inductance and prevent potential differences between local and global grounds, thereby minimizing the influence of other module components on the transmission function.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the ground-side connection of shunt arms is made within the chip or second substrate, then the module structure is more compact and easier to manufacture, but additional module components shift the zero points in the transmission function, causing interference and reduced performance
Solution Approach 1:
The ground-side connections of the shunt arms are extracted from the chip/second substrate and relocated to the first substrate. This separation removes the harmful influence of additional module components on the zero points in the transmission function, while the manufacturing process remains straightforward through standard PCB grounding techniques.
2Reliability
If the ground-side connection of shunt arms is made outside the chip, then parasitic inductance is reduced and zero point stability is improved, but the module complexity increases due to additional connection paths
Solution Approach 1:
The ground-side connections of multiple shunt arms are merged into a common ground surface on the first substrate. This consolidation reduces parasitic inductance and stabilizes zero points while avoiding the need for separate connection paths for each shunt arm, thereby preventing excessive complexity in the module design.
3Reliability
If a common ground surface is used for connecting shunt arms, then potential differences between local and global grounds are prevented, but the required ground surface area increases
Solution Approach 1:
A common ground surface is implemented on the first substrate to create an equipotential region that connects all shunt arms. This ensures that no potential differences arise between local and global grounds, maintaining reliable operation. The ground surface is designed with optimal dimensions to achieve equipotentiality without excessive area consumption.
Data Source
AI summary
An electrical module with a first substrate, and a component mounted on the first substrate is specified. The component includes a second substrate and a chip arranged on the second substrate. In the module, a filter circuit is realized that includes shunt arms connected to ground each with at least one parallel resonator. The parallel resonators are arranged on the chip. The ground-side connection of at least two of the shunt arms to each other is realized outside the chip and the second substrate. The ground-side connection of the shunt arms is advantageously realized in the first substrate or on a circuit board on which the first substrate is arranged.