Eight-Port Radiator Element for Millimeter-Wave Antenna Array

A straddling array antenna element is proposed, easing the thermal design of two-dimensional planar network of millimeter-wave wireless transceivers. The proposed 2x2 element, dual-polarized sub-array module can be surface-mount on a circuit board, leaving enough room and board area below it for a transceiver chip. As a result, chip and antenna share the same side of the circuit board, and the opposite board side can be used for attaching heat sinks. The eight feed ports of the sub-array module are in the form of 16 metal posts. Each pair of post feeds a slot in the ground plane of a metallic box, similar to a patch radiator with feed slot in its ground plane. The resulting antenna covers an impedance bandwidth of more than 8% around 29 GHz, realizes a per-element directivity of 8 dB and shows coupling to other feeds smaller than -14 dB.