Substrate Integrated Waveguide Filter for RF Module Size Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In radio frequency (RF) modules with multiple antennas, the integration of filters to reduce spurious emissions and out-of-band emissions is challenging due to the bulky nature of traditional RF band-pass filters, which increases the size of the module and complicates packaging in densely packed systems.
Innovation Solution
The implementation of substrate integrated waveguide (SIW) band-pass filters within the substrate between antennas and RF front-end circuits, allowing for efficient filtering while minimizing module size by integrating filters within the multilayer PCB structure, facilitating direct or indirect coupling with antennas and RFIC chips.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If traditional RF band-pass filters are integrated into RF modules, then spurious emissions and out-of-band emissions are reduced, but the module size increases and packaging becomes complicated
Solution Approach 1:
The patent combines the RF band-pass filter with the substrate structure itself, integrating the filter into the multilayer PCB rather than using a separate discrete component. This merging of functions allows filtering capability to be achieved without adding external filter components, thereby reducing overall module volume while maintaining emission control performance
Solution Approach 2:
The patent transitions from traditional planar filter layouts to a three-dimensional multilayer substrate integration approach. By utilizing vertical stacking and multiple substrate layers, the filter is embedded within the substrate thickness rather than occupying additional lateral space, effectively reducing the module's footprint while maintaining filtering functionality
2Object-generated harmful factors
If traditional RF band-pass filters are integrated into RF modules, then spurious emissions and out-of-band emissions are reduced, but packaging complexity increases
Solution Approach 1:
The filter structure is merged with the substrate fabrication process itself, using the same laminated construction techniques already employed for the multilayer PCB. This integration eliminates the need for separate filter packaging, mounting, and interconnection steps, thereby reducing packaging complexity while achieving effective emission control
Solution Approach 2:
The substrate serves multiple functions simultaneously: it provides mechanical support, electrical interconnection, and RF filtering capability. By making the substrate multi-functional, the patent eliminates the need for separate dedicated filter components and their associated packaging requirements, simplifying the overall packaging process while maintaining emission control
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 approach effectively reduces unwanted electromagnetic emissions, meets spurious emissions requirements, and allows for a more compact module design by integrating filters within the substrate, enhancing the operational efficiency and reducing interference with other devices.
Implementation Method 1
substrate integrated waveguide (SIW) band-pass filter
Implementation Method 2
SIW band-pass filter is configured to filter an RF signal propagating between the antenna and the interface structure
Data Source
AI summary
A method of operating a radio frequency (RF) module includes filtering, by a substrate integrated waveguide (SIW) band-pass filter, an RF signal propagating between an antenna and an interface structure. The antenna is disposed at a first side of a substrate. The interface structure is disposed at a second side of the substrate opposite the first side The SIW band-pass filter is disposed within the substrate between the antenna and the interface structure. The method of operating the RF module further includes transferring, by the interface structure, the RF signal between the SIW band-pass filter and an RF front end circuit.