ETD

• antenna in package
• d-band
• high density interconnect pcb
• multiphysics analysis
• slot antenna
• substrate integrated waveguide

This thesis presents the design and multiphysics analysis of a sub-THz antenna
module intended for future 6G communications. The study focuses on a Substrate
Integrated Waveguide (SIW) Cavity-Based Slot Antenna operating at a center
frequency of 140 GHz. The device is implemented using High-Density Interconnect
(HDI) technology, featuring a multilayer stackup constructed from copper layers and
Ajinomoto Build-up Film (ABF) dielectric.
The electromagnetic design phase specifically concentrated on dimensioning the radiating slot to ensure its resonance frequency aligns perfectly with that of the
cavity. Additionally, an optimized feeding network employing a SIW-to-Stripline
transition was evaluated. This configuration resulted in a highly resonant structure,
making it the ideal candidate to rigorously verify the frequency detuning induced
by the thermal expansion of the copper elements. To assess the structural integrity,
the research employed coupled electromagnetic, thermal, and mechanical simulations, evaluating the impact of heat generated by CMOS and MMIC under varying
temperature gradients. The findings reveal that the induced mechanical deformations are in the order of micrometers. However, these structural variations lead
to a fluctuation of the impedance matching parameter, which can degrade the system efficiency given the narrow bandwidth of the resonant structure.