An Integrated On-Board Active-Phased Array Antenna for Internet of Things Applications

In this paper, a 2-bit phase shifter circuit based on transistor devices was designed and its integration process with transmission line and antenna unit was investigated. The phase shifter, constructed with transistors and delay lines, demonstrated good insertion loss performance at the operating frequency. A miniaturized microstrip array was also successfully achieved by using high dielectric constant substrates, meeting the specifications of 75 mm element spacing, about 1 GHz operating frequency, and 60° scanning angle capability. The entire system utilized an integrated antenna-on-board architecture, with reliability ensured through the use of through holes and buried blind holes to improve the signal transmission quality. To reduce the influence of external factors on the antenna performance, a broadband design was implemented to achieve impedance matching between the antenna and the back-end. Additionally, the quality of the ground was ensured by effectively interconnecting the antenna reflection ground with other grounds, resulting in a maximum gain of approximately 11.24 dB. This study provides technical support for the miniaturization and high-performance design of active-phased array antenna systems, with potential applications in various fields.