A 1-D Tightly Coupled Dipole Array for Broadband mmWave Communication

A wideband phased array antenna for the use in 5G millimeter-wave (mmWave) mobile terminal is presented. The proposed array antenna was designed based on the tightly coupled dipole array (TCDA) technique to achieve a low profile and broadband impedance matching characteristic. Unlike the previously reported TCDAs implemented with 2D arrays on a vertical ground plane, the proposed 1D array antenna exhibited the maximum beam direction parallel to the ground, which is suitable for mobile terminal applications. Using a full-wave electromagnetic simulation tool, a 1 x 8 TCDA was designed on a multilayer substrate including a reflector surface in the middle to replace a vertical ground plane. Prototypes were fabricated and measured with feeding networks designed for 0 degrees and 30 degrees scanning scenarios. The size of the proposed antenna (excluding the feeding network) was 42.3 x 12.05 x 0.535 mm(3). The measured bandwidth that subjects to S-11 < -10 dB criterion was 22.5-32.5 GHz, which covers most of the worldwide 5G mmWave frequency band candidates at the 20-GHz band range.