Low-profile broadband mushroom and metasurface antennas

We present the recent progress in developing the mushroom and metasurface antennas for low-profile and broadband applications. The metamaterial-based mushroom antenna technology is first developed to realize broadband boresight-radiation with low profile on PCB and LTCC substrates operating from microwave to millimeter-wave bands. As a variation of the original mushroom antenna, vialess metasurface antennas are proposed along with miniaturization technique. Finally, the shorting-wall loaded mushroom antenna with new operating mechanism is reported as well.