Search

A new compact ultra-wideband (UWB) filtering antenna having good band-edge selectivity and suppressed unwanted harmonics is proposed in this paper. The proposed UWB filtering antenna is obtained by integrating modified elliptic-shaped UWB antenna with super-compact UWB bandpass filter (BPF). Initially, a UWB antenna is designed and investigated through numerical simulation and experimentally. Further, the geometrical parameters of BPF are optimized using numerical simulation software for its integration with the proposed UWB antenna to improve the passband selectivity and unwanted harmonic suppression capability of the proposed UWB filtering antenna. The proposed UWB filtering antenna has simulated −10 dB impedance bandwidth of 7.65 GHz (3.07-10.72 GHz) and unwanted harmonic suppression up to 30 GHz. It has nearly stable omnidirectional radiation patterns over whole UWB frequency band. The proposed filtering antenna was fabricated and experimentally tested. The experimental results for the filtering antenna are nearly in agreement with corresponding simulation results. [ABSTRACT FROM AUTHOR]

ABSTRACT To mitigate the interference with coexisting wireless systems operating over 3.3-3.6 GHz, 5.15-5.825 GHz, and 7.725-8.5 GHz bands, a novel triple band notched coplanar waveguide fed pitcher-shaped planar monopole antenna is presented for ultrawideband applications. Bands notched characteristics are achieved using a novel mushroom type electromagnetic band gap structure like resonator and a split ring slot. A conceptual equivalent RLC (Resistor-Inductor-Capacitor)-resonant circuit is presented for the band notched characteristics . Furthermore, the input impedance and VSWR (voltage standing wave ratio) obtained from the equivalent circuit are validated with simulated and measured results. Performances of the antennas in both, the frequency domain and the time domain are investigated. The simulated and measured results demonstrate that the proposed antennas have wide impedance bandwidth, nearly stable radiation patterns, and suppression of gain and total radiation efficiency at notched bands. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:795-806, 2015. [ABSTRACT FROM AUTHOR]

A compact eight-element MIMO antenna for wideband applications with dual-band sharply dispensation characteristics is presented. A same oriented two-element antenna is placed in orthogonal symmetric fashion on an octagon-shaped substrate cross-section area of 0.4374 λ 0 2 (at 3.03 GHz), forms an eight-element MIMO antenna. A combination of stubs between same oriented elements and dual I-shaped stubs between a pair of corner elements are used to the interconnected ground for high isolation. The proposed MIMO antenna achieved a −10 dB measured fractional bandwidth (S ij ∈ i = j) of 133.98% (3.03–15.33 GHz) and obtained a minimum isolation value (S ij ∈ i ≠ j) of 15.5 dB. The dual quarter-wavelength slits are created in each radiator for dual notched-bands at 5.1–5.8 GHz and 6.7–7.3 GHz. The measured and simulated results are found in good agreement. [ABSTRACT FROM AUTHOR]

This paper presents the design of a compact ultra-wideband (UWB) antenna and a frequency reconfigurable antenna with high isolation for cognitive radio (CR) applications. The antenna prototype comprises a UWB antenna for sensing UWB spectrum and a frequency reconfigurable antenna for communication purposes. The proposed antenna has been designed on FR-4 substrate with a compact size of 25 × 36 × 1.6 mm3 (0.22λ 0 × 0.32 λ 0 × 0.014λ 0) , where λ 0 is free space wavelength at 2.7 GHz. The −10 dB impedance bandwidth is realized for UWB antenna ranges from 2.7 GHz to 10 GHz and for frequency reconfigurable antenna in two frequency bands from 4.3 GHz to 5.5 GHz and 5.1 GHz to 6.8 GHz. A T-shaped stub is integrated into the ground plane to achieve high isolation between antenna element ports and the impedance bandwidth improvement. The proposed design attains high isolation of −21 dB over communication frequency range of frequency reconfigurable antenna and most of the UWB spectrum. The prototype has been fabricated and measured. The measurement results are in good agreement with the simulated results. [ABSTRACT FROM AUTHOR]