In this paper, a miniaturized and simple structured antenna designed using Poly-Di-Methyl-Siloxane (PDMS) as substrate is proposed for multi-frequency based wireless portable applications. The antenna offers dual bands around 2.45 GHz for ISM and 5.4 GHz for WLAN spectrum. The antenna has a small size of 24 mm ×24 mm with low profile. The antenna geometry contains a coaxial probe and T-shaped stubs loaded rectangular resonator. The design offers peak gain up to 5.6 dBi and radiation efficiency up to 96%. Whereas, for both operating bands it demonstrates gain >5 dBi and radiation efficiency >82%. Further, to demonstrate its significance the antenna performance in terms of bandwidth, gain, efficiency, and size has also been compared with recently published papers. The presented design is suitable for future portable electronic devices.