Linear array of image NRD guide-based dielectric rod antenna fed by slotted rectangular waveguide

The gains of tapered dielectric rod antennas are determined primarily by their length. However, long tapered rods are difficult to realise and arrays of these antennas are needed if much higher gain is required. In the paper, a linear array of dielectric rod antennas is proposed based on an image NRD guide which employs a slotted rectangular waveguide feed. This array demonstrates the ability to achieve high gain in a simple structure with relatively short tapered rods. First, a single-element dielectric rod antenna is analysed using the FDTD technique to obtain the data for the design of the linear array. Based on the results obtained, the 2-element linear array is designed and analysed. A gain of 22 dB is obtained by the 2-element array using the antenna length of 90 mm (10.6 λ₀). This gain requires an antenna length of about 200 mm (23.5 λ₀), if conventional rod antennas were to be used. Measured results are presented to confirm the effective performance of the proposed array configuration.