# A Transition Structure from Stripline to Substrate-Integrated Waveguide Based on LTCC

## TL;DR

This paper introduces a new transition structure for high-frequency communication systems using LTCC technology, enabling efficient signal transfer between stripline and substrate-integrated waveguide.

## Contribution

A novel stripline to SIW transition structure using LTCC technology is proposed, offering stable performance and manufacturing feasibility.

## Key findings

- The transition structure achieves a return loss below −10 dB from 89–100 GHz.
- Insertion loss is approximately 0.75 dB, demonstrating efficient signal transmission.

## Abstract

With the advancement of wireless communication technologies into high-frequency millimeter wave and sub-THz bands, conventional transmission lines such as microstrip and stripline face significant limitations. Under the circumstances, along with the increased application of new transmission lines such as substrate-integrated waveguides (SIWs), the design of transition structures between different transmission lines has become a practical requirement in modern signal transmission systems. This paper presents a novel stripline to SIW transition structure. Drawing inspiration from the classical microstrip probe techniques in metal waveguides, the proposed design employs Low-Temperature Co-fired Ceramic (LTCC) technology for both device fabrication and SIW implementation. The developed structure demonstrates a stable performance, structural simplicity, and manufacturing feasibility. Through fabrication and testing, the transition structure can achieve a return loss below −10 dB across the 89–100 GHz frequency range, with an insertion loss of approximately 0.75 dB.