Substrate Integrated Waveguides in Glass Interposers for mm Wave Applications

This paper presents the first demonstration of Substrate Integrated Waveguides in glass interposers operating in D-band (110 GHz to 170 GHz) for mmWave applications. The material stack-up consists of 100 µmthick AGC ENA1 glass core laminated with 15 µm thick Ajinomoto Build up Films (ABF GL102) on both sides. The stack-up has been metallized using a newly developed Semi Additive Process (SAP). SIWs have been fed using broadband microstrip taper transitions. Conductor Backed Coplanar Waveguide (CBCPW) to microstrip transitions were designed to probe the samples. Cascade Infinity Probes (170-S-GSG-75-BT) were used for the electrical measurements. The measured insertion loss of glass based SIWs varies from 0.5dB/mm to 1 dB/mm in the entire D-band. For most of the frequencies it varies in the range of 0.5-0.8 dB/mm. The performance of glass interposer based SIWs has been compared with SIWs in LCP and silicon interposer.