  This paper presents the design and comprehensive measurements of a compact
high-gain 32 element planar antenna array covering the n257 (26.5-29.5 GHz)
millimeter wave (mmWave) band. First an 8-element quasi-uniform linear array is
designed using a series-fed topology with fan shaped beams for
point-to-multipoint connectivity followed by a compact corporate series feed
network to design high-gain directive array for point-to-point connectivity.
The radiation patterns of both antenna arrays in the azimuth and elevation
planes are measured across a 180 degrees span using an over-the-air (OTA)
compact antenna test range (CATR) system with a single rotary positioner.
Moreover the procedure for quantifying and measuring the gain of mmWave antenna
arrays is demonstrated in detail. The peak measured gain of the planar array is
18.45 dBi at 28.5 GHz while the half-power beamwidth of the planar array in the
elevation and azimuth planes varies between 11 to 13 degrees, and 23-27 degrees
respectively within the 26.5-29.5 GHz range. The measurement results match well
with the simulations. The designed antenna array is suitable for various
emerging 5G and beyond mmWave applications such as fixed wireless access,
mmWave near-field focusing, high-resolution radar systems, and the
characterization of mmWave path loss and channel sounding in diverse indoor
environments and smart factories.
