A Dual-Band Cavity Antenna Embedded Within Multiple Metallic Enclosures

This work describes the design and evaluation of an antenna to be embedded within multiple metallic cavity like structures of quite arbitrary shape. The design is based on an open substrate-integrated waveguide (SIW) implemented with RO 4003 substrate, aiming to miniature the cavity and suited for fabrication with printed-circuit board (PCB) technology. A pair of vias is used to tune the resonances of the cavity for dual-band operation [2.45 and 5-GHz wireless local area network (WLAN) bands], and an open-loop resonator is introduced to enhance the bandwidth. The cavity antenna is fed by a stripline to avoid cross coupling with other devices. Evaluations have been performed both in freespace (FS) and inside multiple metallic cavities. Operating from within the cavities, a good antenna performance is obtained with a maximum -10-dB bandwidth of 4% at 2.45 GHz and 25% at 5.5 GHz. Simulations and measurements agree well. As a proof of concept, the proposed antenna was connected to several WLAN modules inside realistic metallic cavity environments and its operation was evaluated in a realistic indoor environment. These real-life tests confirm that the maximum data rate of 54 Mb/s is obtained for most practical situations, in which the antenna has to operate.