Shorted Bowtie Patch Antenna With Less Susceptibility to Surface Condition

An antenna with less susceptible to surface condition is proposed in this communication. By adding a pair of parasitic shorted patches at the side of a shorted bowtie patch antenna, very low back radiation can be achieved within entire operating bandwidth. Frontto-back ratio, impedance bandwidth and peak gain are over 30 dB, 12.23% and 6.5 dB, respectively, and confirmed by measurement. The proposed antenna has thickness and projection area of only 0.08 λ₀ and 0.77 λ₀ × 0.77 λ₀. A prototype for 5.8-GHz ISM band application (5.725-5.875 GHz) is also designed. Experimental results confirmed that the reflection coefficient, gain, and radiation pattern have been less affected by mounting on different types of surfaces like human wrist, phantom hand, phantom head, or large metal sheet. Its potential applications include 5.8G Wi-Fi, on-body communication, biometric applications, wearable healthcare, and biomedical devices.