Waveguide Transition Structure for RF Integrated Circuit Modules
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The fabrication of vertical transition elements for radio-frequency integrated circuits is complicated and less compatible with advanced integrated-circuit packaging techniques, particularly at higher frequencies, due to the difficulty in creating vertical pins or antennas with sufficient metal resolution.
Innovation Solution
An integrated-circuit module with a waveguide transition structure embedded in a package molding compound, featuring a transmission line interface, waveguide interface, and a transformer section to transition propagation modes, along with a redistribution layer connecting the RF integrated circuit to the waveguide transition structure, facilitating efficient coupling to rectangular waveguides.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If vertical probe or pin structures are used to transition from transmission line to waveguide, then electromagnetic mode transition is achieved, but fabrication complexity increases and metal resolution decreases
Solution Approach 1:
The patent transitions from vertical 3D probe structures to a planar 2D distributed transformer configuration. The transformer section uses parallel conductors arranged in a planar geometry that achieves mode transition through distributed capacitance and inductance in the horizontal plane, eliminating the need for vertical fabrication processes and associated complexity.
Solution Approach 2:
The waveguide transition structure is divided into distinct functional sections: a transmission line interface section, a transformer section with multiple parallel conductors, and a waveguide interface section. This segmentation allows each section to be optimized independently and fabricated using standard planar processes, reducing overall fabrication complexity while maintaining transition efficiency.
2Reliability
If vertical pins or antennas are fabricated for mode transition, then propagation mode conversion is achieved, but metal resolution and pitch are reduced
Solution Approach 1:
The invention moves the mode transition mechanism from the vertical dimension to the horizontal plane. The distributed transformer uses parallel conductors arranged laterally with controlled spacing, allowing precise metal dimensions to be maintained using standard planar fabrication processes while achieving the required electromagnetic coupling for mode transition.
Solution Approach 2:
The patent changes the geometric parameters of the transition structure from vertical dimensions (probe length, diameter) to horizontal dimensions (conductor spacing, parallel conductor length). This parameter transformation allows the use of high-resolution planar metallization processes while maintaining effective electromagnetic coupling for mode conversion at high frequencies.
3Ease of manufacture
If planar transmission line structures are used for RF interconnects, then ease of fabrication is improved, but coupling efficiency to waveguide at high frequencies decreases
Solution Approach 1:
The distributed transformer section acts as an intermediary between the planar transmission line and the waveguide structure. It provides a gradual mode transition through distributed electromagnetic coupling, maintaining impedance matching and minimizing reflections while enabling efficient energy transfer from the planar TEM mode to the waveguide TE10 mode.
Solution Approach 2:
The transformer section extends in the horizontal dimension with parallel conductors that create distributed capacitance and inductance. This planar extension provides the necessary electromagnetic coupling length to achieve efficient mode transition while remaining compatible with standard planar fabrication processes, thus maintaining both ease of manufacture and coupling efficiency.
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 solution enables a low-loss transition between transmission lines and rectangular waveguides, achieving efficient RF signal propagation with minimal insertion loss and high return loss across a wide bandwidth, specifically optimized for frequencies up to 100 GHz.
Implementation Method 1
a transformer section configured to provide a propagation mode transition between the transmission line interface section and the waveguide interface section
Data Source
AI summary
An integrated-circuit module includes a package molding compound layer, a radio-frequency (RF) integrated circuit embedded within the package molding compound layer and having an RF port, a waveguide transition structure embedded within the package molding compound layer, and a redistribution layer. The waveguide transition structure includes a transmission line interface section, a waveguide interface section configured for coupling to a rectangular waveguide housing, and a transformer section configured to provide a mode transition between the transmission line interface section and the waveguide interface section. The redistribution layer includes at least one insulating layer and at least one metallization layer, extending between the RF integrated circuit and the waveguide transition structure across a surface of the package molding compound layer. The first redistribution layer includes an RF transmission line conductively connected between the RF port of the RF integrated circuit and the transmission line interface section of the waveguide transition structure.