Antenna-array topologies for mm-wave beamforming transmitter with quadrature spatial combining

In this paper, we present several antenna-array topologies for quadrature spatial combining: In-phase and Quadrature signals are not anymore combined at the circuit level but rather spatially in free space. To demonstrate the feasibility of this concept, an organic module with two 4×1 antenna-arrays is fabricated and measured in V-band. Reflection coefficient and realized gain measurements are very promising.