A Novel Programmable Stacked Patch Antenna With the Diversity of Sixteen Linear Polarizations and Four Frequency Bands

A highly multifunctional antenna with multilinear polarizations (MLPs) and multibands (MBs) is proposed, which can operate over four reconfigurable frequency bands, each band having 16 switchable linear polarizations (LPs) at an 11.25° interval. The larger number of MLPs is achieved by developing an odd–even switching strategy for the independently controlled p-i-n diodes placed between the inner patch and outer sector patches. The diode control is enabled by a field programmable gate array (FPGA) with an engineered biasing network. Moreover, the reported antenna can switch among four continuous bands for each LP, covering a combined range larger than 35%. It is an attractive feature, yet a challenging task for an antenna with such a large number of MLPs. This is realized by utilizing a double-layer feeding strategy with appropriate sector-patch activation, which is particularly appealed to such a highly multifunctional antenna. Furthermore, the antenna has a rotational symmetry along the azimuthal direction and, hence, all the LPs show almost rotationally invariant pattern shapes and gains. The measured results are consistent with the simulated ones, commonly validating the effectiveness of our design.