This communication reports significant isolation improvement utilizing planar suspended line (PSL) technique in ultra wideband (UWB) antenna for Multiple Input Multiple Output (MIMO) application. The antenna exhibits dual-band notched characteristic in Wireless Local Area Network (WLAN) band covering 5.45–5.85 GHz range; and in 7.15–7.95 GHz range for X-band downlink operations in satellite communication. Band-notching characteristics have been obtained by employing a single Elliptical Split Ring Resonator (ESSR) placed adjacent to each microstrip feed line of the radiating element and duo of “Y”-shaped strips employed within the circular ring of individual radiating elements. Two elements antenna occupy a compact space of 20 × 36 × 1.6 mm3 exhibiting huge measured impedance bandwidth (S11/S22 < −10 dB) covering 3.1–11.5 GHz and significant isolation of >21 dB in the almost entire band of operation. The electrical performance of antennas has been analyzed in terms of various MIMO parameters. Measured results demonstrate good accord with simulated results proving the competency of proposed antenna in high-density package systems and massive MIMO applications.

We report in this paper a novel miniaturized (12 × 18 × 1.6 mm3) microstrip fed UWB antenna with tunable notched band characteristics. The proposed antenna covers the tunable notched band for IEEE 802.11a wireless local area network operating in the frequency band of 5.15–5.825 GHz. The design of proposed antenna includes annular ring radiating patch with two T-shaped strips present inside it. The band notching is obtained by adjusting coupling between T-shaped strips placed inside the annular ring. In order to achieve larger bandwidth the ground plane of the microstrip antenna is modified. The simulated return loss of the proposed antenna has been verified in fabricated antenna experimentally, which has been in good agreement.

In this paper, two novel coplanar waveguide (CPW) fed printed ultra wide band (UWB) monopole antennas with dual band-notching characteristics are proposed. The modified ground technique with symmetric ground plane in antenna 1 and asymmetric ground planes in antenna-2 is exploited to cover UWB application. Both antennas are compact with dimensions of 30 × 30 × 1.6 mm 3 and have dual band-notched characteristics with first notched band for integrated band of WiMax 3.5/5.5 GHz and C-band satellite communications 3.7-4.2 GHz and second notched band for WLAN 5.2/5.8 GHz bands. Antenna with symmetric ground plane achieves the impedance bandwidth of 2.9-11.5 GHz, and antenna with asymmetric ground plane achieves the impedance bandwidth of 2.9-11.89 GHz, respectively with VSWR < 2 except in the notched bands. The antennas are designed and optimized in CST Microwave Studio. The simulated VSWR of the proposed antenna designs is compared with the measured VSWR of fabricated antennas, and it is found that they are in a good agreement. Both antennas exhibit monopole-like radiation patterns with significant gain in entire operating band. Maximum gain of the proposed antenna with symmetric ground plane is 5.3 dBi at 8 GHz, and that with asymmetric ground plane is 4.5 dBi at 7 GHz.

The present paper reports the gain enhancement over a wideband (12–15 GHz) in a coplanar waveguide (CPW)-fed circular patch antenna with circular defected ground structure (DGS). Two compact coplanar circular antennas have been designed and fabricated with and without DGS of same volume 18 × 20 × 1.6 mm3, built over FR4-epoxy substrate (εr = 4.4). Gain enhancement has been achieved by optimizing the current distribution with suitable DGS. For this purpose, structural designs have been optimized by parametric simulations in HFSS and CST MWS. Both the antennas can perform well in variety of wireless communication including WLAN IEEE 802.11 g/a (5.15–5.35 GHz and 5.725–5.825 GHz) and X-band applications including short range, tracking, missile guidance, and radar communication that ranges roughly from 8.29 to 11.4 GHz. The measured experimental results show that impedance bandwidth (S11 < −10 dB) of antenna with DGS is 100%. The antenna with DGS offers gain improvement by 2.7 dB for 13 GHz and 7 dB for 14 GHz. The performance of antenna with DGS is compared to conventional CPW-fed circular patch antenna (without DGS) in terms of reflection coefficient, radiation characteristics, and gain.

No abstract