Three-Dimensional Surface in LTCC for a MM-Wave Antenna

Abstract

Low loss LTCC (Low Temperature Cofired Ceramics) materials have already demonstrated their virtues for high density packaging of mm-wave modules and their capability to handle the inherent requirements of heat dissipation. A 60 GHz substrate integrated waveguide fed steerable antenna array is one example of the driving applications for new challenges in the LTCC process. This antenna is suitable for transmit and receive in the 60 GHz WPAN frequency band [1]. Integrating antenna array and mm-wave front-end in one module is a consequent way to avoid amplitude and phase uncertainties associated with connectors and cables. A compact module also helps to reduce losses in the signal path by providing short interconnects. This is important for mm-Wave systems, particularly for the receiver. The antenna design presented here requires a three-dimensional surface structure with features like small and precise cavities and grooves. Different methods to fabricate cavities in LTCC modules will be discussed and a new method which proved suitable for the demanding application will be presented in detail.