Dual-Band Implantable Antenna With Open-End Slots on Ground

We present a dual-band implantable planar inverted-F antenna. Besides the resonance at 2.45-GHz Industrial, Scientific, and Medical (ISM) band, three closely spaced resonant frequencies are created at the lower band by adding open-end slots in the ground plane, resulting in a broad bandwidth covering Medical Implant Communication Services (MICS) band at 402 MHz and ISM band at 433 MHz. The measured frequencies range from 356 to 610 MHz (52.6%) at the lower band and from 2.42 to 2.53 GHz (4.4%) at the upper band for |
S
₁₁
| less than - 10 dB. The antenna occupies a compact size of 487.8 mm
³
(19 mm × 19.4 mm × 1.27 mm).