Reseach On UWB Band-notched Antenna And Planar Multiple Bands Antenna

In recent years, the development of modern wireless communication technologies is very fast. As a key component of modern wireless communication systems, the antenna has received wide attention. The development of portable mobile communication equipment stimulates the antenna to develop towards compact size,multi-band and wide band. The planar printed antennas with low cost, easy fabrication,low weight and small size become the primary choice in modern communications equipment.An ultra-wide band antenna with triple notched bands is proposed in this paper.The gradient edge of radiating patch and ground provide the work frequency at 3.1-10.6GHz. A semicircle slot with length of half wave-length is etched in the radiating patch to generate the notched band in 3.3-3.6GHz for WLAN. Two semicircular strips with length of half wave-length are placed both sides of the feed line to create the second and third notched bands in 5.15-5.35 GHz and 5.72-5.83 GHz for WLAN. Within the frequency of 3.1-10.6 GHz, the antenna is nearly omni-directional in H-plane, both the peak gain and the transfer function maintain relatively steady, the fidelity in H-plane detected by probe is above 0.88.Two multi-band antennas are designed. One of the proposed antennas has compact size of 20 × 25 × 0.8 mm3. The antenna consisting of three short strips shows a multiband characteristic covering 300 MHz(2.2-2.5 GHz) 400 MHz(3.3-3.7 GHz) and800 MHz(5.1-5.9 GHz). Each band could be controlled by adjusting the length of the strip. The other antenna adopting co-planar waveguides achieves triple bands of 220MHz(2.33-2.55 GHz) 880 MHz(3.0-3.88 GHz) and 750 MHz(5.15-5.9 GHz). A reversed U shaped slot and a square loop with slit are applied to create notched bands and improve impedance in different bands. Both of the multi-band antennas satisfy the need of WLAN( 2.4-2.484 GHz, 5.15-5.825 GHz) and WIMAX(3.3-3.6 GHz). The antenna models optimized by CST and HFSS are fabricated and measured. The measured results are in good agreement with the simulated results.