Tham khảo tài liệu 'mobile and wireless communications network layer and circuit level design 2012 part 6', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Micromachined high gain wideband antennas for wireless communications 141 Parameter Unit mm Patch length Patch width Patch thickness Slot length 11 Slot width Microstrip length Microstrip width Inner length of cavity 19 Inner width of cavity 19 Cavity height Thickness of polyimide film Thickness of microwave PCB substrate Table 1. Summary of the design parameters for the microstrip fed suspended patch antenna. The height of the polymer rim was adjusted to obtain high gain. In the HFSS simulation the lateral dimensions of the polymer rim were chosen to achieve high efficiency and compact size for the antenna structure. Table 1 summarizes the design parameters of the antenna device. A microwave PTFE material AD300A from Arlon MED http was used as the base substrate while a polyimide thin film Du Pont provided the supporting substrate for the suspended patch. The dielectric constant and loss tangent of the PTFE substrate are respectively 3 and . For the SU8 rim material they are Thorpe et al. 1998 and Lucyszyn 2001 respectively while the corresponding values for polyimide substrate material are and . In order to accurately model the performance of the antenna device the parasitic effects of the SMA connector are simulated by introducing a short and wide rectangular extension at the input of the microstrip feed line. The dimensions of the extension are chosen to match the length and diameter of the pin of the SMA connector. It has been observed that accommodating the effect of the connector is vital in order to accurately model the reflection characteristics of the suspended patch antenna. In the following sections the S11 parameters for estimating the bandwidth normalised radiation pattern and radiation efficiency obtained from the HFSS designer environment are presented and discussed. S parameters and study of the bandwidth To assess the performance of .
