A Compact Microstrip Antenna With Enhanced Bandwidth and Ultra-Wideband Harmonic Suppression

A compact microstrip antenna with enhanced bandwidth and ultra-wideband harmonic suppression is presented in this communication. To broaden the working bandwidth of dipole antenna, U-shaped patch, slender stub, and parasitic patch are applied. To improve the bandwidth of the harmonic suppression, slender stub, parasitic patch, short stub, and U-shaped slot are introduced. The proposed antenna has a wide impedance bandwidth and an ultra-wideband harmonic suppression without extra circuit. In the end, a model antenna with the center frequency 4.3 GHz (f
_C
) is designed and manufactured. The proposed antenna has a fractional bandwidth of 42.8% (3.43-5.3 GHz) and a wide harmonic suppression bandwidth range from 1.4fC to 6.0f
_C
(6.2-26 GHz).