An UWB Ceramic Monoblock Dielectric Rod Antenna with Over 7 Octaves

In this paper, an ultrawideband (UWB) ceramic monoblock dielectric rod antenna (DRA) with over 7 octaves is designed. The DRA is mainly composed of two parts: a ceramic monoblock section and a feeding section. The feeding section is a coaxial line to gold-plated TEM horn structure. This design allows the DRA to operate without radiation mode limitations while effectively improving the continuity of the feeding structure, greatly expanding the antenna bandwidth. As the frequency increases, the dielectric rod excites traveling wave modes, reducing the phase difference between the edges and the center, thereby enhancing the directivity of the antenna. By utilizing the characteristics of TEM horn impedance gradient to increase gain and the high dielectric constant DRA to lower the cutoff frequency, reduce reflection current, widen the bandwidth, it achieves the design of an UWB DRA that an impedance bandwidth from 4.1 GHz to 31.7 GHz for VSWR $\leq 2.0$ (Octave band: 7.73) is covered.