Wide-Narrow Switchable Bands Microstrip Antenna for Cognitive Radios

Abstract

We introduce a six-switch integrated ultra wideband (UWB)-frequency reconfigurable system for cognitive radio applications. With respect to the requirements of the cognitive radio, this proposed design incorporates a UWB section for sensing the frequency spectrum, and the same design is frequency reconfigured using switches to get narrow bands for communicating within the spectrum. The proposed design has a compact size of 40 mm × 40 mm × 1.6 mm and is printed on an FR4 substrate with relative permittivity 4.4. The first configuration of switches allows the antenna to have UWB characteristics from 3.10 to 12 GHz and beyond as per simulations and 3.13 to 12 GHz and beyond as per measurements. Configurations II to V cover the ultrawide band from 3.54 to 12 GHz through five narrow bands. Measured results match well with the simulated ones. The comparative analysis of the antenna in terms of frequency reconfigurability is also included in this work which proves that the proposed design is an effective candidate for Cognitive Radio applications.

Filtenna with Frequency Reconfigurable Operation for Cognitive Radio and Wireless Applications

“…The poles and zeros of ( F N ) are ω pi ′, ω zi ′ , where the F N can be obtained from Equation (2) [ 26 ]. At this stage, the S 11 and S 21 can be extracted using Equations (3) and (4) [ 27 ].…”

“…A wide/dual/single band PIN-based reconfigurable monopole antenna with a band of operation (3.3–7.8 GHz) was introduced in [ 25 ]. A reconfigurable UWB monopole antenna was introduced in [ 26 ] for cognitive radio applications using six switches to obtain five narrow bands.…”

A Frequency Reconfigurable Folded Antenna for Cognitive Radio Communication

“…Some of the employed techniques to achieve multiband behaviour are a fractal structure [ 9 , 10 ], a complementary split ring resonator metamaterial [ 11 ], a window grille cross-structure [ 12 ], a meandered offset-feed [ 13 ], a split ring resonator and inverted F slots [ 14 ], a bowtie slot patch [ 15 ], and DGS and DMS [ 16 , 17 ]. An additional capability that can be possibly integrated with the multiband behaviour of the antenna is the reconfigurability which has a vital role in the accomplishment of cognitive radio applications, and it can be carried out using PIN diodes [ 18 , 19 , 20 , 21 ], varactor diodes [ 22 ], lumped capacitors [ 23 , 24 ], and RF MEMS [ 25 ]. In [ 18 ], a semi-circular patch was loaded onto a triangular radiator with two inverted L-stubs to achieve reconfigurability between two frequency bands using a pair PIN diode.…”

“…A dual-band (2.4, 5 GHz) folded monopole antenna is presented in [ 24 ] for a WLAN application with a lumped capacitor on the front side for size reduction purposes. A UWB antenna with reconfigurable capability is presented in [ 25 ] for cognitive radio applications using six MEMS switches to obtain five frequencies in the C-band.…”