Polygonalization of mm-wave dual-band circular phased arrays for multi-mode beamforming

The modularization of 28 GHz multi-mode circular arrays and 60 GHz phased sub-arrays onto N-sided convex polygons is presented. This includes a study on the basic impact of phase error arising from this mapping and the achievable radiation performance from both bands. The intent of this mapping is to investigate the manufacturability and modularization of dual-band mm-wave phased arrays operating at 28 GHz and 60 GHz. The faceted 28 GHz design is operated as a non-uniform multi-mode array, where the polygon is used to approximate the ideal uniform circular array. This gives rise to a subarray concept for a multi-band (or wide band) antenna that operates as a traditional phased array panel in this architecture. In this work, we constrain the resulting design space to provide an approximation of uniform spacing based on the geometric parameterization of the structure for half-wave spacing in the 28 GHz band. The basic layout of the design is presented first and constrained to examine the error arising from modularization. A wavelength-scaled prototype operating at 2.4 GHz is used to demonstrate the measurement and error of the system.