Millimeter wave (mmWave) Multi Beam Foldable Antenna Array with Tilted Beam holds immense potential for reducing atmospheric absorption, multi-path effects that hinder signal quality at these frequencies, and compact satellite deployment scenarios. However, conventional designs operate in lower millimeter wave spectrum, have complex geometries, don't utilize low-cost air-filled SIW technology (AFSIW), suffer from poor bandwidth, and exhibit poor gain, low scanning coverage, poor pattern re-configurability, don't have tilted and Multiple beams. To address these concerns, an AFSIW Multibeam Foldable Antenna Array with a tilted beam is proposed for the first time based on a Rigid Flex Substrate. The design exhibits a large bandwidth over the entire V-Band, a superior gain of 15.51 dBi, a large scanning coverage, low cost, and superior radiation pattern reconfigurability with a tilted beam. This array finds application in urban-air-mobility (UAM), and satellite communication systems, where mitigating multi-path effects is crucial for enhancing signal quality, and compact deployment is essential. State-of-the-art performance is observed when the work is compared to reported advances in the literature. In conclusion, the work addresses a critical gap and paves the way for cost-effective, high-performance solutions for mmWave communication.

Despite extensive research on integrating Substrate Integrated Waveguide (SIW) technologies with conventional transmission technologies such as Microstrip Transmission Line (MSTL), Co-planar Waveguide (CPW), Rectangular Waveguide (RWG), and Coaxial lines, a comprehensive evaluation and design framework has yet to be explored. This review addresses this critical gap by providing a detailed examination of recent advancements in interconnect technologies at millimeter-wave (mmWave) frequencies. The paper identifies unresolved challenges and introduces a novel Figure-of-Merit (F oM) designed to evaluate and decide the state-of-the-art in interconnect technologies. Furthermore, it proposes a novel design flow that aids interconnect designers by integrating reported advances into a well-defined process. As such, the study provides a basis for further developments in this area and uses the advantages of existing technologies and SIW to ease the integration on mmWave systems.

Millimeter wave tilted beam horn antennas (mmWave) hold immense potential for reducing atmospheric absorption and multi-path effects that hinder signal quality at these frequencies. However, conventional design techniques employ bulky structures, have complex geometries, don't utilize low-cost air-filled SIW technology (AFSIW), suffer from poor bandwidth, and exhibit comparatively poor gain and low elevation scanning coverage. To address these concerns, an AFSIW horn antenna with a tilted beam is proposed for the first time. The design exhibits a large bandwidth over the entire V-Band, a superior gain of 15.51 dBi, and a large elevation scanning coverage. Furthermore, the work also proposes an AFSIW multibeam antenna array utilizing these tilted-beam AFSIW horn antennas for the first time. This array finds application in urban-air-mobility (UAM), and satellite communication systems, where mitigating multi-path effects is crucial for enhancing signal quality. State of art performance is observed when the work is compared to reported advances in the literature. In conclusion, the work addresses a critical gap in tilted-beam antenna design but also paves the way for cost-effective, highperformance solutions for mmWave communication.