Design and Investigation of Disk Patch Antenna with Quad C-Slots for Multiband Operations

An investigation into the design and fabrication of multiband disk patch antenna with symmetrically quad C-slots is presented in this paper. The proposed antenna shows multiband resonance frequencies which highly depend on substrate thickness, dielectric constant, and radius of the disk patch. By incorporating two pairs of C-slots in optimum geometry on the radiating patch, the proposed antenna operates between 2 and 12？GHz at different frequency bands centered at 2.27, 7.505, 9.34, 10.33, and 11.61？GHz. The other antenna parameters are studied like gain, antenna efficiency, and radiation pattern. The proposed antenna may find applications in S-, C-, and X-band. The results are carried out with the aid of HFSS and MOM-based IE3D simulator. The measured and simulated results are in good agreement with each other. 1. Introduction There is increasing demand for antennas having compact size and multiband operation. Since each communication protocol may operate in a distinctive frequency band, instead of using several antennas, it is highly desirable to have one broadband or multiband antenna to meet the needs of multiple systems. Microstrip disk patch antennas are suitable for many wireless communication applications and frequency bands such as S-band (2–4？GHz), C-band (4–8？GHz), and X-band (8–12？GHz). In addition, compact size with multiband operation is a demand factor for several applications such as mobile communication. The demand of multiband antennas is fulfilled by integrating the diode switches, cutting slots of different geometries, multiple narrow slits in rectangular patch antenna, slot antenna with edge-fed, compact fork shaped antenna, and compact slot on the radiating patch [1–4]. There are some other techniques reported in literature to obtain multiband behaviour of the antennas such as employing the two microstrip line feeds placed in orthogonal directions [5] and circular ring antenna with a defected ground plane excited by Y-shape-like microstrip feed [6]. Recently, it has been shown that multiband resonance can be achieved by using edge feeding in two circular slots each having T-shaped patch which highly depends on the diameter [7] and cutting two pairs of orthogonal narrow slits on stacked circular disk [8]. However, some of these antenna structures involve complex calculation, sophisticated design structures, and large size as compared to proposed antenna. In this paper, a quad C-slots disk patch antenna optimized for simplicity in design is proposed for multiband operation. The numerical analysis and geometry refinement of the