Multi-Band Patch Antenna Array for Out-of-Band Aided Millimeter Wave Communication

Abstract

Future wireless communication systems will integrate both sub-6 GHz and millimeter wave (mmWave) frequency bands within multi-antenna architectures to meet the increasing demand for high data rates. In such multi-band systems, reliable information obtained from the sub-6 GHz band can be exploited to support communication at mmWave frequencies. To ensure that both systems experience similar multi-path propagation effects, the sub-6GHz and mmWave antenna arrays have to be colocated and precisely aligned. However, such a configuration may adversely alter the radiation characteristics of the arrays, potentially degrading their performance. In this paper, we investigate the impact of positioning a mmWave antenna structure in front of a sub-6 GHz antenna structure. Through both simulations and measurements, we evaluate how the presence of the mmWave structure affects the radiation pattern of the sub-6 GHz one. The results demonstrate that the influence of the mmWave structure on the sub-6 GHz performance is minor, indicating that co-located configurations are feasible with negligible degradation.

Figures (9)

• Figure 1: The multi-band uniform linear array (ULA) consists of sub-6 GHz and mmWave antenna arrays that are co-located and precisely aligned (sharing the same geometric center) and separated by an inter-array spacing of $h_{\rm a}$.
• Figure 2: On the top layer (left), each patch element, with dimensions $l_{\rm p}^{\left( {\rm b} \right)} \times w_{\rm p}^{\left( {\rm b} \right)}$, is fed by a microstrip line of width $w_{\rm m}^{\left( {\rm b} \right)}$ and features an inset feed of dimensions $l_{\rm cut}^{\left( {\rm b} \right)} \times w_{\rm cut}^{\left( {\rm b} \right)}$. The bottom layer (right) consists of a solid copper ground plane.
• Figure 3: A MMW ULA with variable size (8-element, 16-element or 32-element) is positioned in front of the single sub-6 GHz patch antenna.
• Figure 4: The realized gain of the sub-6 GHz patch element in the main lobe direction is approximately 7.96 dBi, with a negligible degradation of around 0.12 dB when the MMW array is present.
• Figure 5: Measurement setup for field-pattern measurements conducted in the anechoic chamber at TU Wien.