A compact microstrip patch antenna having a 2-dimensional grounded-pad array embedded in an LTCC substrate

This paper proposes a new approach to reduce the size of the patch antenna by embedding a 2D grounded-pad array in an antenna substrate. Periodically installed grounded-pads are expected to exhibit slow-wave effects. First of all, a microstrip delay line having a 1D grounded-pad array in its substrate is demonstrated theoretically by the conventional FDTD method, and the slow-wave effect is discussed in section 2. Next, a 2D grounded-pad array is applied to a microstrip patch antenna to reduce the size of the antenna, and experimental results are shown in section 3 together with the theoretical ones. In the experiment using a prototype model, an LTCC substrate, which is suitable for multi-layer structures, was adopted.