# Antenna-on-Chip for Millimeter Wave Applications Using CMOS Process Technology
## 2 Structure, Mechanism, and Design
On the other hand, in an AMC with a regular array size of \(9\times 11\), its bandwidth is \(31\) GHz, with a minimum reflection coefficient (S11) of \(-27\) dB at a standard reflection coefficient of \(-10\) dB. Therefore, an AMC with a regular array size of \(9\times 11\) is chosen. Figure 11: Reflection coefficient of W\({}_{8}\) variation. Figure 12: The periodic array size of the proposed AMC: (**a**) Type 1 regular array size is \(7\times 9\); (**b**) Type 2 regular array size is \(9\times 11\). Next, the reflection phase of AMC in the M1 layer is analyzed. Figure 14a is the AMC unit model designed in this paper. It can be known from Figure 14b that the AMC designed in this paper has a phase bandwidth and a high reflection coefficient at an operating frequency of 60 GHz. In Figure 15, parameter analysis is also performed through the presence or absence of M1 AMC. Figure 16 shows that when the AMC is designed with the M1 layer, a lower value of the reflection coefficient (S11) can be obtained. However, when AMC is designed without the M1 layer, the bandwidth cannot continuously reach the standard \(-10\) dB of the reflection coefficient. Therefore, by comparing the simulations, it is possible to analyze the influence on the reflection coefficient of the antenna when designing the AMC with or without the M1 layer. Figure 14: (a) Artificial magnetic conductor simulation model; (b) Reflection magnitude and phase for AMC. Figure 13: Reflection coefficients (S11) of different periodic array sizes of AMC. In terms of probe GSG grounding, as shown in Figure 17, in this paper, a circular hole is drilled in the probe grounding area, and the simulation diagram is shown in Figure 18. When the probe GSG grounding area has no holes, and the frequency is 60 GHz, the minimum reflection coefficient is only \(-14\) dB, and the bandwidth is 31 GHz. Then, through the penetration method of the hole in the GSG grounding area, impedance matching is achieved so that the 60 GHz frequency band can reach the standard reflection coefficient of \(-10\) dB, the minimum reflection coefficient can reach \(-26\) dB, and the bandwidth can reach 32 GHz. Figure 16: Simulation diagram with and without AMC. Figure 15: Geometry of the proposed antenna-on-chip: (**a**) Without the M1 layer of AMC; (**b**) With the M1 layer of AMC. As shown in Figure 19, this paper analyzes the antenna's architectural operation through the current distribution. The antenna designed in this paper uses the probe GSG method to feed the signal, which excites the antenna body to generate the surface current. The current is distributed to the antenna body through the CPW structure of the feeding line. Figure 19a,b show the current distribution state at 38 and 60 GHz. In the 34 GHz to 65 GHz frequency band, the area where the current distribution is more obvious is the area of the tapered patch and its surrounding area. It can be judged that the resonance of the tapered patch antenna generates this frequency band. Figure 17: The geometry of the proposed antenna-on-chip: (**a**) Design no holes in the GSG grounding area; (**b**) Design holes in the GSG grounding area. Figure 12.0 Reflection coefficient of probe GSG grounding with or without holes.