Compact Uwb Antenna With Tunable Band-Notch Characteristics Using Varactor Diode

Abstract

A compact ultra-wideband (UWB) antenna with tunable band notched characteristics is proposed. Varactor loaded, two via edge located (TVEL) and fractal electromagnetic band gap (EBG) structures are designed for tunable band-notched characteristics. The varactor diode near the TVEL EBG tunes the band-notch frequency for WiMAX (2.8-4.0 GHz) band, while another varactor near fractal EBG structure tunes band-notch frequency for WLAN (4.7-6.2 GHz) band. The varactors are independently controlled to achieve WiMAX and WLAN notched band. Notch frequencies can be continuously tuned by varying the bias voltage across the varactors. The proposed antenna of 24 × 24 mm 2 dimensions is fabricated on an FR4 substrate. A good agreement between simulation and measurement results is obtained. A continuous band notch tuning from 2.8-4.0 GHz and 4.7-6.2 GHz is obtained using varactor diodes having capacitance in a range of 0.497-2.35 pF.

Tunable Triple Band-Notched Uwb Antenna Using Single Ebg and Varactor Diode

“…Various techniques are employed in band-notched antennas to produce notches at specific frequency of interest. However, these band notches are achieved by etching slots on radiating elements, using resonators or with multi-parasitic elements around the feed line [7][8][9][10][11][12][13][14][15][16][19][20][21][22][23][24][25][26][27][28][29][30][31]. In order to achieve multiple band-notches, UWB antennas should not only make effective use of the space around the radiating patch but also be able to minimize coupling effects with less parasitic elements near the feed line.…”

“…12(a) and (b), respectively. Previously, various reconfigurable band-notched antennas using more active devices such as capacitors and varactors have been reported in [19][20][21][22][23][24][25][26][27][28][29][30][31]. In [19], open loop resonators (OLRs) are used around the feed line of antenna to produce single band-notch, and the antenna is tuned from 5.1 to 5.9 GHz using two varactors embedded in the OLRs.…”

“…In [30], triple band notching and tuning are achieved with open ended stubs and three varactors, respectively. In [31], two EBG structures, namely TVEL and fractal, are used to produce dual band notches at WIMAX and WLAN bands, respectively. The EBG structures are loaded with two varactor diodes and tuned independently between 2.8-4.0 GHz and 4.7-6.2 GHz.…”

“…The EBG structures are loaded with two varactor diodes and tuned independently between 2.8-4.0 GHz and 4.7-6.2 GHz. The works reported in [19][20][21][24][25][26][27][28][29][30][31] have either managed to produce tunability with more varactors/capacitors or are able to tune only single notch-band [22,23]. Considering the power supply constraints and biasing circuit's complexity, it is always desirable to design multi-band notch antennas with minimum active devices for continuous tuning.…”

A Switchable Triple-Band Notched Uwb Antenna Using Compact Multi-via Electromagnetic Band Gap Structure

“…Previously, many techniques were proposed to provide band-notching. In [13][14][15][16][17][18][19][20], these band notches are achieved by etching slots on radiating elements, using resonators, or with multi-parasitic elements. However the technique of inferring the antenna to get notch bands affects the performance of antenna.…”