A Compact Dual Band Rectangular Dielectric Resonator Antenna With Slot for Wban

Abstract

I. INTRODUCTIONThe DRA antenna is a very attractive alternative for applications at wireless communications. The different types DRAs such as cylindrical, rectangular, and hemispherical shapes [2]- [10] have been presented in literature. Cylindrical and rectangular dielectric resonator antennas are having attractive features over the triangular and hemi sphere shapes. A new dual band hybrid structure [2] to achieve dual frequency operation for WBAN applications is proposed. The proposed structure can be considered as the combination of DRA and other radiating resonator, such as a slot resonator [3]. These two elements are tightly stacked together and resonate at two different frequencies. The resonant modes corresponding to each resonant frequency is different from each other. Their radiation patterns have different performance for WBAN applications.The use of dielectric resonators [4] in feeding circuits requires accurate knowledge to couple the resonators and circuits. In order to match the DR to the feed line and to excite the desired mode in the resonator, the most common feeding technique is the aperture-coupled [5] arrangement. However, the resonant feeding structure adopted in these reported designs, such as microstrip-fed aperture-coupled, co-axial probe coupling, co planar slot feed and CPW-fed slot arrangement offers more flexibility and is directly compatible with different mounting surfaces. In this letter, in order to avoid via holes, the microstrip feed line is proposed [6]. The microstrip line [11] printed on the same substrate excites a dielectric resonator (DR) that could be placed directly over the feed line. The advantage of microstrip feed is easy to fabricate, simple to match by controlling the inset feed position, low spurious radiation and easy to model.To demonstrate the idea, the proposed hybrid dual-band antenna [7] is designed for wireless body area networks. It consists of upper (2.4 GHz) and lower (403 MHz) frequencies of the dual-band antennas [8] are primarily controlled by the DRA and slot respectively. The designed dual-band antenna has the maximum radiation directed toward the inside of the human body in the medical implantable communication service (MICS) [18]-[20]band in order to collect vital information from the human body [9], and directed toward the outside in the industrial, scientific and medical (ISM) band to transmit that information to a monitoring system. This design has the advantage of small size, simple structure and can achieve dual frequency operation with different radiation patterns.