A compact filtering antenna with high band-edge gain selectivity using a composite right-/left-handed (CRLH) resonator and a defected ground structure is presented. The CRLH resonator resonates at the zeroth-order mode and acts as the first stage of the corresponding filter; an octagonal patch acts as a radiator as well as the last stage of the filter. The design procedure follows the circuit approach -synthesis of bandpass filters. The filtering antenna has two poles in the passband and two radiation nulls (zeros) at the band edges. Compared to the conventional patch antenna, the proposed filtering antenna, with little extra circuit area, has flat gain response within the passband, good selectivity at the passband edge and wider bandwidth. Measurement results show that the filtering antenna can operate at 5.29 GHz, has a 430 MHz bandwidth and a 2.5 dBi antenna gain in the broadside (+Z ) direction within the passband.Introduction: In modern wireless communication technology, one of the issues is integrating multiple functional circuitries into one device to achieve miniaturisation and improved performance. The filtering antenna is a new concept that could realise both filtering and radiation functions, which avoids designing the antenna and the bandpass filter separately, and achieves the more compact devices and improves the performance of microwave front ends. Different from direct connection of the filter and the antenna by an extra impedance transformation structure, several studies on filtering antenna design which follow the filter synthesis that the antenna acts as one of the resonators have been presented in [1][2][3][4][5], such as a fan-shaped patch antenna with a circular openloop resonator [1], a U-shaped patch antenna with a T-shaped resonator [2], an Γ-shaped antenna with a coupled line resonator [3], an Γ-shaped antenna with two square open-loop resonators [4] and an inverted-L antenna with parallel coupled microstrip line sections [5].In this Letter, using a miniaturised composite right/left-handed (CRLH) resonator and an octagonal patch antenna with a defected ground structure (DGS), a new compact two-pole filtering antenna is proposed (Fig. 1). The CRLH resonator consists of an inter-digital capacitor and four metallic vias, resonating at zeroth-order mode, so that the size of the structure could be more flexible and compact than the conventional half-wavelength resonator. The octagonal patch antenna with the DGS acts as a radiator as well as the second resonator. The filtering antenna has a flat gain response within the passband and good selectivity at the passband edge. The measured results are in good agreement with the simulated ones.

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Abstract-A compact triband asymmetric coplanar strip (ACS)-fed monopole antenna for WLAN/WiMAX applications is proposed and investigated in this paper. The proposed antenna is composed of an ACS-fed folded monopole and two inverted-L branches, which occupies a very compact size of 26.5 × 12 mm 2 including the ground plane. By carefully adjusting the lengths and positions of these branches, three desired resonant frequencies can be achieved and adjusted independently. The antenna exhibits three resonances covering the 2.4/5.8 GHz WLAN bands and 3.5 GHz WiMAX band. Details of the antenna design, simulation, and experimental results are presented and discussed. The proposed antenna shows nearly omnidirectional radiation characteristics and moderate gains in the operating bands. The compactness, simple feeding technique and uniplanar design make it easy to be integrated within the portable device for wireless communication.

Abstract-This paper reports a new delay subspace decomposition (DSD) algorithm. Instead of using the canonical zero-delay correlation matrix, the new DSD algorithm introduces a delay into the correlation matrix of the subspace decomposition to suppress noises in the data. The algorithm is applied to functional magnetic resonance imaging (fMRI) to detect the regions of focal activities in the brain. The efficiency is evaluated by comparing with independent component analysis and principal component analysis method of fMRI.Index Terms-Functional magnetic resonance imaging (fMRI), independent component analysis (ICA), noise suppression, principal component analysis (PCA), subspace decomposition.