Design of Differential-Fed High Performance 60 Ghz Microstrip Antenna Array

This project develops two differential-fed 60 GHz 4x4 microstrip antenna arrays with low cross polarization level, wide bandwidth, high antenna gain, and symmetrical radiation patterns. In Design 1, each patch element is differentially fed by two coupled slots with differential signals to suppress cross polarization level and improve the asymmetrical radiation patterns. The novel substrate-integrated waveguide (SIW) H-plane differential series-fed network, SIW E-plane differential parallel-fed network, and 180° power divider are designed, which have the advantages of low insertion loss and easy integrating to antenna array. The proposed 4x4 differential antenna array achieves high gain, low cross polarization level, and symmetrical radiation patterns. In Design 2, patches fed by L-shaped feeding structure are used as element antennas for raising bandwidth. A modified feeding structure is proposed to reduce design complexity. Design 2 is composed of differential pairs of single-ended patches, each of which is fed by either 0° or 180° signals. Although the patch elements are single ended, Design 2 is differential when viewing this array as a whole. The feeding network of SIW T-junction, layer transition structure, and 180° power divider are design with low insertion loss. This project develops a novel strip-via soft-surface structure possessing wide stopband and small size, which can be added in between of two antenna elements to suppress surface wave and enhance the antenna gain largely. The proposed 4x4 differential antenna array achieves wide bandwidth, high gain, low cross polarization level, and symmetrical radiation patterns.

Project ID:PB10507-2947
External Project ID:MOST105-2221-E182-010