Design of a dual-notched ultra-wideband (UWB) planar antenna using L-shaped bandstop resonator

Slotted Printed Monopole UWB Antennas with Tunable Rejection Bands for WLAN/WiMAX and X-Band Coexistence

“…Over the last 5 years, numerous techniques were applied in order to create the rejected bands on such type of antennas. The most common approaches were the stop-band feature developed in [11][12][13][14][15][16][17][18][19][20][21], whilst the [11][12][13][14][15] were designed with only a single notched band, that are not suitable for multi-notch band communication applications. Therefore, the design of an UWB antenna with dual band notch characteristics is becoming a very challenging task.…”

“…Therefore, the design of an UWB antenna with dual band notch characteristics is becoming a very challenging task. To meet this challenge, various design techniques have been implemented to accomplish dual notch-band characteristic within the UWB range [16][17][18][19][20][21].…”

“…However, the frequency of most notched-band UWB antennas [11][12][13][14][15][16][17][18][19][20][21] are uncontrollable after their fabrications, which fail to meet the needs of reconfigurable notchedbands in real-time. Thus, the reconfigurable technique has received significant attention in the field of wireless communications.…”

“…In summary, it is found that most of the antennas in [11][12][13][14][15][16][17][18][19][20][21] only provide either UWB designs with fixed single band suppression as in [11][12][13][14][15], or with dual notched features as in [16][17][18][19][20][21]. It should be noted, that the antenna designs in [11][12][13][14][16][17][18][19][20] operate in the UWB spectrum, except at WiMAX and WLAN systems, where the notched bands were created. However, there is still a wide frequency spectrum from 6 GHz to 11 GHz, in which those UWB antenna designs may share part of this frequency spectrum with adjacent spectral systems leading to interference at several applications and communication systems such as radar, space and satellite.…”

“…Thus, designs in [15], [21] were proposed to avoid the envisaged interference that may take place around the X-band spectrum. However, all the proposed structures in [11][12][13][14][15][16][17][18][19][20][21] have fixed single/dual rejected bands, which cannot be altered/modified once these designs are fabricated. Therefore, it is required to design an UWB antenna with reconfigurable notch characteristics.…”