Series-Fed Integrated Lens Antenna for High Gain in Millimeter-Wave Band

This letter proposes an integrated lens antenna (ILA) that uses a patch as a feed structure to achieve high gain in the millimeter-wave (mmWave) band. The proposed ILA consists of a patch for feeding and an elliptical dielectric lens and can be extended from a single antenna to an array antenna. This letter covers the implementation of single ILA, 2 $\boldsymbol{\times }$ 1 ILA array, and 4 $\boldsymbol{\times }$ 1 ILA array. A series-fed network was applied for patches for low loss and small size. The proposed antenna can reduce the overall volume because it has an integrated structure without separating the lens and series-fed patch. The dielectric lens was fabricated using a 3-D printer and integrated with the printed circuit board, on which the series-fed patch was printed to implement the ILA. The simulated peak gains of single ILA, 2 $\boldsymbol{\times }$ 1 ILA array, and 4 $\boldsymbol{\times }$ 1 ILA array are 15.1, 16.6, and 18.1 dBi, respectively, while measured peak gains are 14.0, 15.3, and 16.8 dBi, respectively. The proposed 4 × 1 ILA array has a small size of ${{\text{1.8}}\lambda _{0}\times {\text{5.1}}\lambda _{0}\times {\text{1.6}}\lambda _{0}}$ due to the integrated lens design and is suitable for high frequency wireless applications as it can be easily integrated with radio frequency systems.