The invention belongs to the technical field of antenna, and provides an LTCC double-layer single-feed circularly polarized
microstrip patch array antenna unit, for solving the contradiction that a current circularly polarized
microstrip patch array antenna needs to consider both low profile,
circular polarization, high
gain, and
broadband development. In the LTCC double-layer single-feed circularly polarized
microstrip patch array antenna unit, an upper layer of
radiation metal patch and a lower layer of
radiation metal patch are different in the size; the resonant frequency point of the lower layer of
radiation metal patch is higher than the
center frequency of the antenna unit; the resonant frequency point of the upper layer of radiation metal patch is lower than the
center frequency ofthe antenna unit; the chamfer size of the lower layer of radiation metal patch is greater than the chamfer size of the upper layer of radiation metal patch; and the chamfer size of the upper and lower
layers of radiation metal patches enables the
single point feed square patch to generate two orthogonal degeneration
modes with the same amplitude to form a 90 DEG
phase difference. The LTCC double-layer single-feed circularly polarized
microstrip patch array antenna unit utilizes the upper and lower radiation metal patches with the same shape and different size, thus being able to preferably consider both the performance demands for low profile and
circular polarization of the microstrip patch
chip, and greatly improving the
frequency band bandwidth of the antenna.