Abstract—The IEEE 802.11ax/be standard, known as WiFi 6/7, represents the latest evolution in Wireless Local Area Network (WLAN) technologies. Due to their high data rates and improved capacity, these standards are critical for supporting current and next-generation Internet of Things (IoT) applications. Operating across three frequency bands—2.4 GHz, 5 GHz, and 6 GHz—with bandwidths exceeding 300 MHz, these standards present significant challenges for antenna design, particularly in creating multiband antennas that maintain resonance at all desired frequencies while ensuring wide bandwidth and high gain. This study proposes a novel multiband antenna structure based on a double circular geometry optimized for operation at 2.47 GHz, 5.08 GHz, and 6.07 GHz. The antenna demonstrates high directionality (over 6.1 dB) and maintains a stable maximum radiation direction across all bands, addressing a key difficulty in multiband antenna design. Additionally, the antenna achieves wide bandwidths exceeding 460 MHz, effectively covering the frequency ranges for both IEEE 802.11ax/be and 802.11bd standards. Performance validation was conducted using CST simulation, VNA measurement, and real-world WiFi system testing, and the S11 simulation and measurement result agreed well. The Received Signal Strength Indicator (RSSI) and the Signal-to- Noise Ratio (SNR) of the proposed antenna are better than those of commercial dipole antennae in a real-world WiFi system. This design offers a practical solution for future IoT and high-performance WLAN applications, contributing to the development of compact, efficient, and reliable multiband wireless communication systems.