An optimized micro-gated terahertz detector with novel triple resonant antenna is presented.The novel resonant antenna operates at room temperature and shows more than a 700% increase in photocurrent response compared to the conventional bowtie antenna.In finite-difference-time-domain simulations,we found the performance of the self-mixing GaN/AlGaN high electron mobility transistor detector is mainly dependent on the parameters L gs(the gap between the gate and the source/drain antenna) and L w(the gap between the source and drain antenna).With the improved triple resonant antenna,an optimized micrometer-sized AlGaN/GaN high electron mobility transistor detector can achieve a high responsivity of 9.45×102 V/W at a frequency of 903 GHz at room temperature. An optimized micro-gated terahertz detector with novel triple resonant antenna is presented. The novel resonant antenna operates at room temperature and shows more than a 700% increase in photocurrent response compared to the conventional bowtie antenna. In-finite-difference-time-domain simulations , we found the performance of the self-mixing GaN / AlGaN high electron mobility transistor detector is mainly dependent on the parameters L gs (the gap between the gate and the source / drain antenna) and L w (the gap between the source and drain An improved micrometer-sized AlGaN / GaN high electron mobility transistor detector can achieve a high responsivity of 9.45 × 102 V / W at a frequency of 903 GHz at room temperature.