Compact Low-Cost Phased Array of Dielectric Resonator Antenna Using Parasitic Elements and Capacitor Loading

A three elements compact low-cost phased array of rectangular dielectric resonator antenna (RDRA) is presented. The scanning phase is based on using mutual coupling and capacitor loading. The center DRA is made of high dielectric constant, ε r =35.9 and fed by a microstrip line. The two parasitic dielectric resonators (DRs) are electromagnetically coupled to the driven element. The dielectric constant and dimensions of the parasitic element are quite similar to the driven dielectric resonator. The phase shift between elements is adjustable by changing the reactive loading on the parasitic DRs. The reactive loadings are two small capacitors inserted between the microstrip lines and ground plane. The scan coverage of the phased array antenna is ±30 degrees at 2.8 GHz. Across the entire scan angle range, the array return loss is less than 10 dB across a bandwidth of 130 MHz.