Miniaturization of Planar Monopole Antenna for Ultrawideband Radios

The miniaturization is described of a beveled planar monopole antenna in low temperature coflred ceramic technology for integration with ultrawideband radios. We demonstrate through simulations that a 40% reduction in size can be realized by simply exploiting its structural symmetry. We find that the miniaturized beveled planar monopole antenna exhibits wider impedance bandwidth, higher cross-polar radiation, and slightly lower gain at higher frequencies as compared with its un-miniaturized counterpart. We confirm the miniaturization with the measurements of both un-miniaturized and miniaturized beveled monopole antennas. The miniaturized beveled monopole antenna of size 17 × 10 × 1 mm³ has achieved impedance bandwidth of 8.25 GHz from 2.85 to 11.1 GHz, gain from -5.6 to 2.3 dBi, and broad patterns. Both frequency domain and time domain characteristics of the beveled monopole antennas are also carefully investigated with a normalized measured transfer function.