Millimeter-wave filtenna for 5G application with multiple controllable radiation nulls and wide stopband

A filtenna (filtering antenna) for the fifth generation (5G) mobile communications in millimeter-wave (mmWave) band is proposed in this paper. The filtenna is fed by a probe, and two radiation nulls are generated at the upper sideband based on the stacked-patches structure. Then, two shorting pins loaded on the driven patch are introduced, which then result in the third radiation null. An "X-character" shape radiation loop is added therefore, the fourth radiation null can be generated. Besides, the fifth radiation null at around 34 GHz is generated by adding four parasitic strips on the top radiation patch. The measured -10 dB impedance bandwidth of the filtenna is from 23.07 to 30.99 GHz. The average gain of the antenna is larger than 5.5 dBi, and the stopband suppression can reach 14 dB with a wide stopband. With the merits of low profile, wide stopband, and stable radiation, the proposed filtenna can be a good candidate for 5G mmWave applications.