《A Filtering Microstrip Antenna Array》.pdf

2856 IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 59, NO. 11, NOVEMBER 2011 A Filtering Microstrip Antenna Array Chin-Kai Lin and Shyh-Jong Chung, Senior Member, IEEE Abstract—A new filtering microstrip antenna array is presented. patches were introduced for multiple mode operation in [1]–[4]. The antenna elements, together with the very compact feeding net- Several antennas in different forms, such as slot dipole antennas work, function as a third-order bandpass filter. The feeding net- [5], [6], monopole antennas [7], microstrip antennas [8]–[11], work, which consists of one power divider and two baluns, pro- vides the first two stages, and the microstrip antenna elements pro- and substrate integrated waveguide (SIW) slot antennas [12] are vide the last stage in the filter design. The equivalent lumped cir- also integrated with BPFs. cuit model is analyzed, and the detail synthesis procedure is pre- Additionally, over the last few decades, the microstrip an- sented. A third-order filtering 2 2 microstrip antenna array is tenna array has become one of the most popular candidates for designed at a center frequency of 5 GHz with 3% fractional band- highly directive antenna applications because of its characteris- width and Chebyshev 0.3-dB equal-ripple broadside antenna gain response. The results from circuit model, full-wave simulation, and tics of low profile, light weight, low cost, and easy fabrication. measurements agree well. Compared to the conventional patch an- For the requirement of high directivity, the number of antenna tenna array, the proposed filtering microstrip antenna array suc- elements tends to increase, and the feeding network must be ce