Design and analysis of a combination antenna with rectangular dielectric resonator and inverted L-plate

A wide-band compact antenna combining a rectangular dielectric resonator (DR) with a grounded and inverted L-plate. is proposed. Two different impedance matching-circuits, a vertical T-shaped strip attached to one side of the DR and a microstrip stub terminated into a T-branch, are introduced to enhance the impedance matching and. to economize the space utilization by the matching circuits. A two-step procedure is applied to design the radiation element and the feed structure of the antenna. Approximate formulas are used to obtain initial estimation of the. antenna dimensions. Then finite-difference time-domain method (FDTD) with the help of fast Fourier transform/Pade method is used for One-tuning. these dimensions to obtain satisfactory resonant frequency and quality factor. Next, the feed structure is designed and adjusted to obtain the optimal impedance matching. Since the radiation element and the feed structure are designed separately, the design process,is simplified and both their performances are optimized within the frame of design restrictions. Two antennas, for 2.4 and 5.8 GHz,Bluetooth and wireless local-area network applications, are designed as examples. The -10 dB bandwidths between 210 and 240 MHz are obtained. The antenna gains are 1.0 and 1.5 dBi, respectively.