Planar Elliptic Broadband Antenna with Wide Range Reconfigurable Narrow Notched Bands for Multi-Standard Wireless Communication Devices

A planar elliptic broadband antenna with reconfigurable dual stop-bands performance was successfully designed and performed for multi-standard wireless communication systems. The proposed antenna consists of a broadband micro-strip fed printed monopole operating in the frequency range 0.75- 6 GHz. The notch-band characteristic was obtained by printing two Open Loop Resonators (OLRs) on the front side of the substrate close to the micro-strip feed-line. By adjusting the OLRs parameters, mono or dual band-rejection can be obtained. The passive broadband antenna was optimized to achieve narrow band rejection over the UMTS-band (around 2.1 GHz) and the WiMAX-band (around 3.5 GHz). The agility was produced by loading a varactor diode on each OLR. The major advantages of this structure are the high selectivity of the dismissed-bands, continuous reconfiguration and wide tuning range of the notched bands. Four prototypes were realized and experimentally characterized. The measured tuning ranges corresponding to the notched bands are about 850 MHz (2.25-3.1 GHz) for the rejected UMTS-band and 570 MHz (3.84-4.41 GHz) for the WiMAX-band. Simulated and measured results are presented and discussed.