In this paper, a 28 GHz fifth-generation (5G) phased array antenna with air-hole slots for beam width enhancement is proposed. The proposed antenna consists of eight dipole radiators on a mobile handset-sized ground with air-hole slots between the two adjacent elements for enhancing the half power beam width (HPBW) in the elevation plane. The dimensions of the proposed antenna are 130 mm × 42 mm × 0.127 mm. The proposed array antenna satisfies a −10 dB reflection coefficient in the frequency range from 27.2 to 29.2 GHz with a peak gain of 10.33 dBi and a side lobe level (SLL) of 13 dB. In addition to its good performance, the proposed antenna has a very wide HPBW (measured) in the elevation plane, up to 219 degree with a scan coverage of ±45 degree in the azimuth plane. The proposed antenna demonstrates excellent hemispheric beam coverage for 5G mobile handset devices and can enable cost-effective mass production.

This communication proposes a compact, wideband, two-port substrate-integrated waveguide (SIW) antenna with a central, double-slotted metallic plate flanked by two paired corrugations for radar applications. The proposed antenna uses a two-layer structure, with a slotted metallic plate with corrugations on the top layer and an FR-4 substrate SIW on the bottom layer. The antenna has compact dimensions of 63 mm $\times$ 54 mm ( $2.32\lambda _{0} {\times}\,\, 1.99\lambda _{0}$ ) with a low profile of 7 mm ( $0.26\lambda _{0}$ ). To understand the operating principle of the two-port SIW antenna clearly, modal analysis is performed for single-port SIW antenna. The antenna satisfies a −10 dB reflection coefficient from 10.15 to 11.58 GHz. Although the separation between the two central slots is minimized to 4 mm ( $0.14\lambda _{0}$ ), the isolation performance remains excellent (less than −30 dB). The gain enhancement, with a narrow beam pattern for radar applications, is realized using constructive superposition of in-phase electromagnetic energy from the two slots. In addition, because the antenna has two ports, it also has a beam scanning function from −12° to +12° in its boresight direction. The experimental and simulated results from the proposed antenna are in good agreement.

모듈형 능동위상배열 레이다에서 모듈 교체 시 발생하는 위상 편차는 필수적으로 보정되어야 하나, 기존 근전계 기반 보정 방식은 과도한 시간과 비용을 요구하여 실용성이 낮다. 본 연구에서는 별도의 근전계 시설 없이 배열 주변에 배치된 안테나를 활용하여 위상 오차를 보정하는 기법을 제안한다. 제안된 방식은 동일 조건에서 반복적인 측정에도 RF 특성이 유지됨을 바탕으로 교체 모듈의 대표 채널만을 측정함으로써 전체 소자의 위상 오차를 효과적으로 보정할 수 있다. 정상 상태 패턴 대비 모듈 교체하고 보정 전/후 패턴을 상관계수, RMS 위상 오차, SLL 변화를 통해 정량적으로 비교한 결과, 제안 기법으로 복원된 패턴이 초기 보정 상태와거의 동일한 수준임을 확인하였다. 이를 통해 제안된 방식이 외부 환경에서도 신속하고 비용 효율적인 모듈 교체 보정을 가능하게 함을 실험적으로 입증하였다.