Miniaturized Dual/Multiband Antenna for Wireless Applications

Abstract

In last decade, there is vast development in communication field especially in wireless applications. Wireless applications cover GPS, GSM, Bluetooth, WLAN, WiMAX bands. GPS gives location access from anywhere wirelessly, Bluetooth transfers file without any physical connection, WLAN and WiMAX provides access of data wirelessly. WLAN (Wireless Area Network) and WiMAX (Worldwide interoperability for Microwave Access) both wireless applications are growing at a very fast rate in present era. WLAN and WiMAX both provide mobility and flexibility to user as he can move in a large area without signal disconnection. In present time, there is large demand for the antennas which can integrate many standards in single device. To cover all the standards, antenna should be wideband or multiband. But as the bands are increasing, size of antenna is increasing, so designing of small antenna is very difficult, for reception or transmission of information large bandwidth is required and small sizes antenna which can be placed in small size equipment. So researchers are working on the techniques to gain small size, multiband and wideband antenna. All of these requirements are fulfilled by microstrip patch antenna which is single layered structure. The presented work here includes the designing of antenna with microstrip line feeding technique using cavity model and transmission line model. The effect of slot and DGS is studied here which provides multiband, large bandwidth, and reduced size. The triangular and rectangular patch shapes are used here for WLAN and WiMAX applications. In this thesis, the rectangular patch which is cut into staircase with etched L-shape slot from ground as DGS geometry is presented which is of small size and provides proficient gain, return loss, radiation pattern and value for VSWR less than 2. This Staircase patch antenna provides band which shows resonance at 3.48 GHz and 5.73 GHz for WLAN and WiMAX applications. And triangular patch antenna provides bands at 3.38 GHz and 5.25 GHz, providing large bandwidth and proficient return loss. Both the antennas are fabricated and tested for practicality of design. Testing of antenna is done by VNA (Vector Network Analyser). Both the antennas provide dual band which can be used to cover present scenario demands.