In this paper, a hybrid zeroth-order resonance (ZOR) patch antenna with a broad <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</i> -plane beamwidth is presented. In order to obtain the broad beamwidth of an antenna, a TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">010</sub> (λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> /2) mode and a ZOR mode are combined. By dividing the incident power to two modes, the <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</i> -plane beamwidth of a TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">010</sub> mode can simply be controlled. To generate the TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">010</sub> mode and the ZOR mode, simultaneously, the mushroom antenna is inserted in a rectangular patch antenna with an etched rectangular hole and a single feed is employed between two radiators. The incident power to each antenna can be controlled by using the gap of a feed. Thus, the optimum incident power ratio having the broadest <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</i> -plane half power beamwidth (HPBW) is obtained. As a result, the <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</i> -plane HPBW of the proposed antenna is measured as 115° and broadened by 53%, compared with that of the conventional rectangular patch antenna. Moreover, the bandwidth and the efficiency of the antenna are measured to be 3.3% and 92%, respectively. Finally, the measured results show good agreements with the simulated ones.