An Antipodal SIW-Fed Vivaldi Antenna at D-Band in LTCC for Flip-Chip RFIC Integration

This paper introduces a single-element antipodal Substrate Integrated Waveguide (SIW) feed for a Vivaldi antenna at D-band, integrated in a Low Temperature Co-fired Ceramics (LTCC) interposer. Analysis and measurement of the SIW loss in the LTCC substrate is provided over D-band (110-170 GHz). Achieving measured peak gain of 6.4 dBi and covering most of D-band, the antipodal Vivaldi can be arranged into linear arrays with flip-chipped radio-frequency integrated circuits (RFICs). This work demonstrates the feasibility of integrating antipodal SIW Vivaldi antennas in LTCC for D-band applications, paving the way for scalable RFIC packaging solutions in next-generation communication and radar systems.