## 7 Conclusions  
This work presents the design of an antenna system to improve ground target detection and tracking performances in a DVB-S-based PR. The main challenge is achieving a wide azimuth beamwidth with high gain, which will provide wider coverage than commercial parabolic dish antennas. Reflectarray antennas can be designed for generating contoured beams, but optimization methods must be used for that task. An innovative design method is proposed based on optimizing the position or steering of some partially overlapped beams, instead of optimizing all the phase distribution, for generating a sectorial beam. The different cell element distribution over the reflectarray is optimized by selecting the best phase for the central one. The design procedure is checked by designing a reflectarray antenna suitable for locating it in the structure of a commercial dish antenna, and with challenging requirements for the surveillance channel of a PR. Geometric design variables as well as feed and cell element selection are studied to obtain the best results. The designed reflectarray antenna was simulated in ANSYS HFSS and checked that its radiation pattern fulfilled the requirements of achieving a sectorial beam of 9.4\({}^{\circ}\) in azimuth plane and 5.4\({}^{\circ}\) in elevation, with a maximum gain of 19.13 dBi. A prototype was manufactured and characterized through measurements in an anechoic chamber, proving the simulation results.  
The reflectarray was validated for its use as surveillance antenna in PR by carrying out trials in two real terrestrial scenarios with the IDEPAR demonstrator. The real acquisition results fit in really well with previous coverage studies, being able to detect cars at a maximum distance from the PR of almost 600 m in the second deployment scenario. These results show a clear improvement in detection and tracking performances with respect to previously published results.  
Conceptualization, J.R.-S., M.-P.J.-A. and D.M.-M.; methodology, J.R.-S., J.-Y.D., J.L. and C.M.; software, [PERSON]-[PERSON]; validation, [PERSON], [PERSON] and C.M.; formal analysis, [PERSON]-[PERSON]-[PERSON], [PERSON] and J.L.; investigation, [PERSON]-[PERSON]; resources, [PERSON]-[PERSON]-[PERSON], [PERSON] and [PERSON]; data curation, [PERSON]-[PERSON], [PERSON]-Y.D., J.L., C.M.; writing--original draft preparation, [PERSON]-[PERSON]; writing--review and editing, [PERSON]-P.J.-[PERSON], [PERSON]-[PERSON] and [PERSON]; visualization, [PERSON]-[PERSON], [PERSON], C.M.; supervision, [PERSON]-[PERSON], [PERSON] and [PERSON]; project administration, [PERSON]-[PERSON]; funding acquisition, [PERSON] and [PERSON]. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Spanish Ministry of Science, Innovation and Universities under project RTI2018101979-B-I00 and the Region of Castilla-La Mancha under project SB-PLY/19/180501/000350.  
**Institutional Review Board Statement**: Not applicable.  
**Informed Consent Statement**: Not applicable.  
**Data Availability Statement**: Not applicable.  
Figure 18: Maps of cumulative detections at the output of CA-CFAR, tracker tracks with their associated detections and GPS ground truth (only for scenario 1).