# A 0.18 um CMOS Millimeter Wave Antenna-on-Chip with Artificial Magnetic Conductor Design
## 5 Conclusions  
A chip antenna is a good candidate for millimeter wave system applications requiring high integration and broadband characteristics. This paper proposed a small-size broadband antenna which was suitable for a millimeter wave system, using a 0.18 \(\upmu\)m CMOS  
Figure 18: Radiation pattern: (**a**) 42 GHz; (**b**) 72 GHz. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Ref.** & **Process** & **Frequency (GHz)** & **\({}^{*}\)****FBW (\%)** & **Gain (dBi)** & **Size (\(\boldsymbol{\lambda^{2}}\))** \\ \hline This Work & 0.18 \(\upmu\)m CMOS & 72.5 & 103.4 & \(-\)6.23 & \(1\times 1\) \\ \hline
[8] & 0.28 \(\upmu\)m CMOS & 33 & 16.3 & 14 & \(0.25\times 0.32\) \\ \hline
[19] & 0.13 \(\upmu\)m CMOS & 81 & 31.4 & \(-\)0.35 & 0.09 \(\times\) 0.04 \\ \hline
[20] & 0.13 \(\upmu\)m SiGe CMOS & 81.5 & 12.1 & 1.61 & 1.21 \(\times\) 1.41 \\ \hline
[21] & 0.65 \(\upmu\)m CMOS & 28, 60 & 5.3, 5.9 & \(-\)10, 0 & 0.17 \(\times\) 0.2 \\ \hline
[22] & 0.18 \(\upmu\)m CMOS & 71 & 9.4 & 8.8 & 1.22 \(\times\) 1.22 \\ \hline
[23] & 0.18 \(\upmu\)m CMOS & 40 & 53.4 & 3.3 & 0.5 \(\times\) 0.78 \\ \hline
[24] & CMOS & 94 & 6.3 & 5.85 & 3 \(\times\) 3 \\ \hline
[25] & CMOS & 60 & 9.8 & \(-\)2.32 & 1.03 \(\times\) 0.51 \\ \hline
[26] & 0.13 \(\upmu\)m BiCMOS & 84 & 11.7 & \(-\)0.58 & 0.3 \(\times\) 0.09 \\ \hline
[27] & MEMS & 28.5 & 13 & 6.6 & 0.17 \(\times\) 0.17 \\ \hline \end{tabular}  
* FBW: Fractional bandwidth.  
\end{table} 
Table 3: Comparison of works in recent years. process, with size 1.2 \(\times\) 1.2 (mm\({}^{2}\)). Metal_6 layer was used as the antenna design, and the Metal_1 layer introduced a square patch and ground plane to form the AMC structure. According to the parameter analysis, when the AMC was covered with the Metal_1 layer, 103.4% bandwidth could be obtained. In addition, the technology of the strip, L-shaped slot, and additional C branch was also used to increase the bandwidth of the antenna. The bandwidth of the proposed antenna is 34.8 GHz-110 GHz, which achieved 103.4% bandwidth. The actual measured bandwidth was 33.8 GHz-110 GHz, and the simulation and measured bandwidth were similar. It had a peak gain of \(-\)6.3 dBi at 72 GHz. The chip antenna proposed in this paper covers the 5G NR FR2 band (24.2 GHz-52.6 GHz) and W-band (75 GHz-110 GHz), which can be applied to the Internet of Things, Industry 4.0, biomedical electronics, near-field sensing and other fields. Its small size makes it easy to integrate with other microwave circuits, and it can form a highly integrated millimeter wave system. In the future, it will be able to integrate with microwave circuits or combine with printed circuit boards to improve the antenna gain performance further. Conceptualization, M.-A.C., methodology, M.-A.C., C.-C.H., S.-R.H. and P.-R.H.; software, M.-A.C., C.-C.H., S.-R.H. and P.-R.H.; validation, M.-A.C., C.-C.H., S.-R.H. and P.-R.H.; formal analysis, M.-A.C., C.-C.H., S.-R.H. and P.-R.H.; investigation, M.-A.C., C.-C.H., S.-R.H. and P.-R.H.; resources, M.-A.C.; data curation, M.-A.C., C.-C.H., S.-R.H. and P.-R.H.; writing--original draft preparation, M.-A.C., C.-C.H., S.-R.H. and P.-R.H.; writing--review and editing, M.-A.C., C.-C.H., S.-R.H. and P.-R.H.; visualization, M.-A.C., C.-C.H., S.-R.H. and P.-R.H.; supervision, M.-A.C., C.-C.H., S.-R.H. and P.-R.H.; project administration, M.-A.C.; funding acquisition, M  
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