A Wideband Coplanar L-Probe-Fed Slot-Loaded Rectangular Filtering Microstrip Patch Antenna With High Selectivity
Chunling Chen
Abstract
A coplanar L-probe slot-loaded wideband filtering microstrip antenna is proposed in this letter. The filtering properties are realized by the introduction of four slots and a coplanar L-probe. A standard TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">20</sub> mode is excited to attain the radiation null at the lower band. Moreover, a standard TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">21</sub> mode and the L-probe contribute to the two radiation nulls at the upper band. The slots also excite new resonant modes to enhance the bandwidth of the antenna. The analysis reveals that a traditional TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">01</sub> mode and a reshaped TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">21</sub> mode are excited and couple with each other to realize a wide bandwidth. The measurements reveal that the proposed antenna has a 10 dB impedance bandwidth of 14% from 2.32 to 2.63 GHz with a peak gain of 9.24 dBi at 2.48 GHz. The gain variation is less than 1 dB within the passband. The advantages of simple structure, coplanar, easy fabrication make the proposed antenna suitable for various wireless communication systems.