Packaged Ultrabroadband Terminal Antenna for 45 GHz Band IEEE 802.11aj Applications

A packaged ultrabroadband terminal antenna is proposed and investigated in this paper for the 45-GHz band IEEE 802.11aj applications. A pair of dual-dipole-element connected by metallic vias is adopted as the terminal antenna with a lower radiation pattern ripple. Then, a substrate integrated waveguide (SIW) open-cavity is used to reduce the mutual interference between the antenna and the inner circuits and make the bore sight gain of the antenna versus operation frequency more stable. Lastly, a broadband broadside coupled dual line- to-SIW transition is also designed with a low return loss in an ultrabroadband. The measured S
₁₁
amplitude is below -10 dB from 36 to 50 GHz, and below -15 dB from 38 to 46.5 GHz and 47.5 to 48.5 GHz. The radiation pattern ripple of the H-plane in the positive-half-space is low (below 1.2 dB from 42.3 to 48.4 GHz, and below 2 dB from 36 to 50 GHz). Meanwhile, the negative-half-space radiation, or the radiation toward circuit board, is reduced remarkably, improving the isolation between the antenna and the circuit nearby. The calibrated bore sight gain of this antenna is about 4 dBi. The performance of antenna is not sensitive to the size of the substrate or the relative position of the antenna. The electromagnetic simulation software HFSS was used for simulating the antenna, and the measured results are in good consistence with the simulations.