Reconfigurable UWB Antenna Research Articles

A Surrogate Modeling Approach for Frequency-Reconfigurable Antennas

A novel generalizable surrogate modeling approach is specifically developed for frequency reconfigurable antennas. The generalizable modeling processes is based on the rigorous mathematical derivation, including the solution of a non-linear overdetermined system, the optimization in the complex field, and the interpolation in multi-dimensional continuous space. As a post-processing method, the approach can convert the discrete data of CAD simulation to a surrogate model. Subsequently, a reconfigurable UWB antenna with a tunable notch-band is taken as an example to demonstrate that the surrogate modeling approach is feasible, effective, and precise. It also has the flexible ability to adapt to strict requirements and complicated scenarios. The proposed surrogate model is a good candidate for the interface standard between a reconfigurable antenna and signal processing part in a Cognitive Radio system.

Design of compact reconfigurable UWB antenna with WiMAX and WLAN band rejection

Two reconfigurable UWB antennas with band rejection characteristics are presented in this paper. By applying concept of parasitic element and etching slot in these two proposed antenna design WiMAX and WLAN band rejection are obtained, respectively to avoid potential electromagnetic interference (EMI). The proposed antennas are printed on 30mm x 40 mm Rogers5880 substrate. Furthermore, ideal switches are employed to achieve switchable band rejection UWB antenna.In this paper, two designs of reconfigurable UWB antenna with band rejection were proposed; namely a reconfigurable UWB antenna with WiMAX band rejection (Antenna 1), reconfigurable UWB antenna with WLAN band rejection (Antenna 2). The proposed antennas were successfully simulated, fabricated and measured. The Antenna 1 have impedance bandwidth from 2.99 GHz to 10.58 GHz with band rejection at 3.52GHz by utilizing C-shaped parasitic stripline. Meanwhile, Antenna 2 achieved an operating bandwidth from 2.99 – 10.82GHz with VSWR less than 2 except for the WLAN band operating at 4.92 – 5.84 GHz.The measured results for both antennas show good agreement with simulated ones.

Band-notched reconfigurable CPW-fed UWB antenna

A reconfigurable band-notched CPW-fed UWB antenna using electromagnetic bandgap (EBG) structure is proposed. Two structures are positioned adjacent to the transmission line of the UWB antenna. The band-notched characteristic can be disabled by switching the state of switch place at the strip line. The EBG structure produces reconfigurable band notched at 4.0 GHz, which covers C-band satellite communication (3.625–4.2 GHz) systems. The proposed antenna is suitable for UWB systems, which requires reconfigurable band reject function.

Optically Controlled Reconfigurable Band-Notched UWB Antenna for Cognitive Radio Applications

By utilizing two optically controlled microwave switches (OCMSs) to control two independent narrow-band complementary split ring resonators, an optically controlled aperture ultrawideband antenna capable of generating reconfigurable multiband notches is proposed. Four reconfigurable states are achieved in the 3.1–10.6-GHz band: 1) a full FCC-allowed band; 2) a WiMax-notched band; 3) a WLAN-notched band; and 4) a WiMax-WLAN-notched band. These bands are useful to detect the available spectra or block the harmful interference from WiMax and/or WLAN systems by simply changing the ON/OFF states of the OCMSs with no more than 100-mW optical powers for each switch. A prototype of the proposed antenna is fabricated and measured. Both simulations and experiments demonstrate the proposed design.

Reconfigurable Antenna With a Diversity Filtering Band Feature Utilizing Active Devices for Communication Systems

Presented in this article is a novel, reconfigurable UWB antenna with a diversity notched band. By switching the pin-diode and tuning the varactor to a certain location along the slot of the antenna, the selection of an operating filtering band is achieved. The antenna is constructed using a FR4 substrate with a thickness of 0.8 mm and having the er value equal 4.4. The band-notch function is produced by inserting an inverted U slot on the radiating patch. Using two PIN-diodes in the slot of the radiation patch, the tunability of the created notch is possible by loading the slot with a lumped varactor. Using the embedded varactor, an electronically controlled notched band antenna is designed and fabricated including a single varactor diode with a varying capacitance value of 0.63-2.67 pf. Moreover, a notched band tunability of 2.7-7.2 GHz is obtained. In addition to the ON/OFF PIN-diodes, the switches yield a band filter which can be suppressed at any given moment.

Compact reconfigurable UWB antenna integrated with SIRs and switches for multimode wireless communications

A kind of reconfigurable wide slot UWB antenna integrated with stepped impedance resonators (SIRs) and ideal switches is presented. The proposed antenna 1 has dual notch band functions which are obtained by using two stepped impedance stub loaded SIRs. The three reconfigurable models are investigated and discussed. The measurement results with ideals switches demonstrate the performances of proposed reconfigurable antennas. The designed reconfigurable antennas can be suitable for future multi-mode wireless communications systems.