Multi-band Slot Antenna

Abstract

A small-size printed antenna is developed for the application of mobile phones. The architecture of antenna bases on the concept of coplanar waveguide (CPW) feeding with slot design. The antenna is planned by an inverted triangular monopole structure with the overall size of 50 mm×120 mm(shown in Fig.1). The proposed antenna was fabricated on PCB with FR4 dielectric substrate. The substrate thickness is 1.6 mmwith the relative permittivity of ~ 4.45. The slots are added to adjust resonance frequency and achieve characteristic of multi-band, which may cover the applications of GPS, GSM (Global System for Mobile Communications), UMTS (Universal Mobile Telecommunications System), and LTE (Long Term Evolution). By the trial of simulation to tune the design of slots, an optimum design of antenna can be obtained. Fig.2 presents the simulated and measured return loss of the antenna. Even though, there are few minor differences between the simulation and measured data. The measured and simulated results still can agree with each other. The achieved bandwidths are 0.54 to 1.01 GHz, 1.34 to 2.28 GHz, and 2.55 to 2.90 GHz, while the return loss ( ) is limited more than 6 dB. This antenna is well suitable for the using of mobile phone applications.