In this article, a printed triangular‐shaped monopole antenna is proposed for emerging ultrawideband application. The proposed antenna uses a triangular radiating patch which is directly fed by a 50‐Ω microstrip feed line. To improve the impedance bandwidth, a round‐corner ground plane has been used. To further improve the impedance bandwidth for the entire band, a microstrip transition (near the antenna front end) has been introduced between the microstrip feed line and the triangular radiator that provides a wide impedance bandwidth from 1.8 to 15.0 GHz for
true|S11true| ≤ −10 dB. The proposed antenna has been realized using the FR‐4 printed circuit board substrate and occupies a small size of about 24 × 30 × 1.6 mm3 compared to conventional antenna structures. The proposed antenna has nearly omni‐directional radiation pattern and moderate gain throughout the operating frequency region. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1155–1159, 2014