A novel differential-fed frequency beam scanning antenna with low sidelobe

In this letter, a novel differential-fed frequency beam-scanning antenna is introduced. This differential structure is achieved by leveraging quasi-Yagi radiating elements within a four-layered geometry. Within this configuration, the element is excited by a pair of out-of-phase slow-wave meander lines, through which differential signals are transmitted. These lines can be seamlessly integrated with other differential circuits. To ensure robust coupling, a broadside coupling structure is incorporated between adjacent layers. To corroborate theoretical insights, a prototype was constructed and tested. Measurements have shown that the primary beam can be scanned from -33.5 degrees to +32.6 degrees on a lateral plane, covering an operational frequency band of 9-11 GHz. Throughout this frequency range, a consistent peak gain of approximately 16.4 dBi is observed for the antenna.