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A novel electromagnetic (EM) lens with high gain, suppressed side-lobe level (SLL) and low profile is designed using thin planar metasurfaces. The proposed design consists of a source patch antenna and an EM lens based on two thin planar metasurfaces. The two thin metasurfaces with an air gap are placed at the focal distance H of about λ /2.25 above the source patch antenna. This configuration forms a thin planar lens in which the source patch antenna emitted quasi-spherical wave in order to transform into plane wave. The total size of source antenna and an EM lens is same. The miniaturised EM lens antenna faces high SLL, which can be reduced by maintaining the uniform transmission phase coefficient and tunable transmission amplitude coefficient of metasurface unit cells. By implementing this topology on metasurfaces, the SLL of the proposed EM lens can be reduced without affecting the boresight gain of source patch antenna. The measured results of the proposed EM lens achieve 7 dB gain enhancement at designed frequency (5.8 GHz) with the SLL suppression of -24 dB. The total volume of planar lens antenna is 1.17 λ × 1.17 λ × λ /2.25 mm 3 , which is very compact compared with other reported planar lens designs.

A new hybrid-antenna that is capable of wide-bandwidth operation and is small size is presented. The structure of the proposed antenna consists of a cylindrical dielectric resonator, metallic posts that are embedded in the resonator, and a rectangular patch. The proposed design generates three resonances: the full-cylindrical HE11δ , half-HE11δ -like mode, and radiation by the patch antenna. An electromagnetic analysis using a finite integration method (CST microwave studio) was performed to investigate the resonances. Furthermore, a prototype of antenna has fabricated for the experimental verification. The simulation results are in close agreement with the experimental findings. The proposed antenna offers a fractional bandwidth of 16.5% at the centre frequency of 9.27 GHz and a peak gain is >4.56 dBi in the matching band.

As an alternative standard electromagnetic (EM) field generator, a 4-port TEM (transverse EM) cell can be used for an EM compatibility (EMC) emission and immunity test. However, unwanted EM fields generated in a TEM cell deteriorate the results and accuracy of critical EMC tests. A new method to suppress unwanted field components in a 4-port TEM cell is proposed. To reduce the unwanted EM field, the narrow slits in internal septa are inserted, which are transverse with respect to the direction of wave propagation. By introducing the slits, the 4-port TEM cell can provide improved standard EM field distribution with the much-lowered unwanted field component inside the usable test volume.

A novel substrate integrated waveguide (SIW) cavity backed slot antenna with low back radiation is proposed in this study. This newly proposed meta-mushroom antenna uses a SIW cavity to decrease the back radiation. It is fed by the SIW cavity backed slot and radiates by meta-mushroom structure. This antenna exhibits broadband characteristics due to the meta-mushroom structure and a bow-tie slot on the SIW. The back radiation of the proposed antenna is considerably diminished by the SIW cavity located at the back side maintaining high gain performance. After all, its front-to-back ratio is increased and maintained over 19.2 dB in the operating frequency band, 4.5–5.6 GHz. Full-wave simulation and experiments results of the proposed antenna are demonstrated.

Human body communication (HBC) is a new technology for mobile and wearable devices operating over body area networks. In HBC, the body is used as a medium for transmitting data between devices to replace wired and wireless technologies. This study examines the bit error rate (BER) degradation experienced by HBC systems under the presence of co-channel interference. A degradation model is proposed to estimate the change in BER, and a selective simulation method is proposed to obtain the BER performance with a small exceedance probability and a small number of BER samples.

A novel microstrip patch antenna is proposed for automotive application. The antenna design has been investigated through both the parametric study and the demonstration of surface currents on the antenna structure. The surface currents related to the co-polarisation increased, and those related to the cross-polarisation is reduced by attaching shorted parasitic element. The four types of single antenna are designed to compare of gain and cross-polarisation level. The cross-polarisation level of proposed antenna has been reduced by 5.9 dB compared with the rhombic antenna. The rhombic array antenna and proposed array antenna were fabricated and tested for input reflection coefficient and radiation performance. The measured and simulated results have been presented and discussed.

A new broadband electromagnetic wave absorber based on a periodic surface and a method to increase its absorption bandwidth is proposed. The proposed absorber structure shows broadband characteristics, and its bandwidth is improved by generating additional resonances through a reasonable approach. To provide an understanding of the logical design procedure, an analytical method to determine the sheet resistance and new equivalent circuit models for analysing the impedance are both presented. From the analysis, it is shown that the exact range of the sheet resistance corresponding to the desired absorption level can be efficiently estimated for the resonance of the structure. For the verification of this approach to obtain an efficient design, as well as the functionality of both the absorber and the proposed method, experimental results are demonstrated along with analytical and computational results. The final measured results using the proposed method show a broadband reflectivity response, with a fractional bandwidth of approximately 93% below −10 dB and a bandwidth increase of 17%.

An investigation of a novel cylindrical dielectric resonator antenna (DRA) configuration has been carried out. It is shown that two resonances including the full- and half-cylindrical HE(11δ)-like modes can coexist simultaneously at different frequencies by placing a metallic post array in the resonator. Moreover, compared with the conventional HE(11δ) mode cylindrical DRA having the same size, the proposed antenna operates in lower frequency band and shows improved bandwidth. The experimental results including the return loss and the radiation patterns are demonstrated.

A novel multi-band reconfigurable antenna for a mobile base-station is proposed. This antenna can be operated in three bands using three radiators, but the radiators are physically combined into one body in consideration of size reduction and optimal performance. Radiator 1 is a square patch structure and is operated in 0.824-0.894 GHz for cellular service. Radiator 2 provides multiple mobile services in 1.75-2.48 GHz for personal communication service (PCS), wideband code division multiple access (WCDMA), world interoperability for microwave access (WiMAX) and WiFi, and thus has a wideband characteristic using a printed dipole structure. Finally, radiator 3 has a stacked structure composed of a radiating and a parasitic patch in 3.3-3.6 GHz for WiMAX2. Radiator 1 has a cylindrical cavity in the centre of the patch, and is designed not to degrade electrical performance, and radiator 3 is embedded in the cavity of radiator 1. Radiator 2 is composed of four printed dipoles and is vertically stacked on radiator 1 around radiator 3 with a rectangular formation. All radiators can provide dual-polarisation using multi-ports controlled by a switching circuit with a control program. In the switching circuit, there are two MEMS switches for band selection. Using the proposed structure, the authors realise a novel multi-functional reconfigurable antenna using three individual radiators.

A printed wide-slot antenna with a centred rectangular parasitic patch, fed by a fork-like tuning stub with rectangular parasitic elements adjacent to the main feed line is proposed and discussed. The proposed wide-slot antenna eliminates the need of rotation of the slot and parasitic patches both in the ground plane for the improvement in impedance bandwidth. The experimental results indicate that the presented antenna has a bandwidth (-10 dB) of more than 148% ranging from 2 to 13.5 GHz. The total size of the proposed antenna configuration is 44.3 × 44.3 × 0.508 mm 3 .

A reverberation chamber (RC) is modelled using a finite-difference time-domain (FDTD) method. To evaluate the performance, firstly, the electric field distribution and then the spatial correlation are computed inside the chamber using the FDTD method. In this work, dipole antennas operating at 750 MHz are used in transmitting and receiving mode. Empirical cumulative distribution functions obtained from FDTD simulations and measured S21 are compared with the Rayleigh distribution. The spatial correlation of the electric field inside the RC is computed from the FDTD-simulated and measured results and compared with published correlation functions.

A low-profile monopole antenna covering the following frequency bands is proposed for mobile phone applications: Global System for Mobile Communications (GSM-900), Digital Communication System (DCS), Personal Communication Services (PCS), Universal Mobile Telecommunications System (UMTS), Wireless Broadband (WiBro), Bluetooth, Satellite-Digital Multimedia Broadcasting (S-DMB), and Wireless Local Area Network (WLAN) frequency bands in the 5.0 GHz range. Multiple resonators in a compact configuration have been used to realise the octa-band internal antenna within a volume of 2.08 cm3 that is very attractive for multifunctional slim handsets. Measured performances of a prototype antenna have been compared to predicted results.

A horn antenna having dual-band and dual-polarisation operation is proposed. To implement a small-sized structure providing circular polarisations in the Ka- and K-band, the antenna is designed using the horn radiator on the basis of a conical helix which is exited by two ports for TX and RX in both ends. Through a design optimisation process, a compact dual-band and dual-polarised horn antenna having high gain and high isolation performance was realised.

A microstrip antenna with dual-band and dual-polarisation operation, realised by electromagnetically feeding using a microstrip-T junction and CPW-line, is proposed and discussed. Since both ports of the antenna are electromagnetically coupled and separately placed on both layers of a substrate, the proposed antenna eliminates the need for capacitors in the RF path for multi-layered active antenna applications.

An internal planar inverted-F antenna (PIFA) for 2.4 GHz Bluetooth and 5 GHz WLAN applications is presented. The proposed antenna has an impedance bandwidth of 110 MHz in Bluetooth band and 900 MHz near 5 GHz in WLAN band within 2:1 VSWR, and an approximately omnidirectional radiation pattern can be obtained. These features are suitable for 2.4/5 GHz WLAN applications.

An internal modified monopole antenna for DVB-H band is presented. By extending the feeding line of the modified monopole and locating it over a ground plane, a wideband input impedance of 328 MHz within 6:1 VSWR is achieved. The proposed antenna has an approximately omnidirectional radiation pattern and yields greater than -3 dBi antenna gain covering DVB-H band. These features are suitable for DVB-H applications

A novel ultra-wideband antenna with band elimination characteristic is presented, which has omnidirectional patterns in the E-plane and impedance bandwidth of about 3-18 GHz with VSWR below 2. The proposed antenna is fed by microstrip line, and consists of the monopole type with two parasitism-patches rejecting 5.15-5.825 GHz bandlimited by IEEE 802.11a and HIPERLAN/2.

A low profile dual-band antenna for WLAN applications is proposed. It has the folded non-uniform meander line with the impedance bandwidth of 140 MHz at the 2.4 GHz band and 1500 MHz near 5 GHz with VSWR below 2, and an omnidirectional radiation pattern is obtained.

A compact and novel modified planar inverted-F antenna (PIFA) for dual ISM-band application is proposed. The proposed antenna, including a small ground plane, occupies a volume of 20/spl times/23.7/spl times/0.8 mm/sup 3/ (FR-4). The impedance bandwidth with 10 dB return loss is about 150 MHz (2380-2530 MHz) for 2.4 GHz band and 1450 MHz (5130-6580 MHz) for 5 GHz band. The measured radiation patterns are approximately omnidirectional and yield a gain of 1.0 dBi at 2440 MHz and 3.98 dBi at 5600 MHz, respectively.

The effect of silver coating on pure indium bumps for low temperature and high speed flip-chip applications is presented with respect to optoelectronic and microwave characteristics. The current-voltage and light power-current characteristics of flip-chip bonded vertical-cavity surface-emitting laser (VCSEL) arrays are improved by coating a thin silver layer of 0.2 µm. The flip-chip assembled coplanar waveguide packages using silver coated bumps show the insertion loss is about 3.3 dB/cm at 20 GHz and the return loss is under 13 dB.

A printed compact dipole antenna for dual ISM band (2.44 and 5 GHz) is presented. The proposed antenna fed by using a 50 /spl Omega/ coaxial line occupies a volume of 15/spl times/40/spl times/1 mm/sup 3/ (FR-4, permittivity 4.6). The impedance bandwidth for 10 dB return loss is about 400 MHz (from 2170 to 2570 MHz) at 2.4 GHz band and over 2300 MHz (from 4690 to beyond 7000 MHz) at 5 GHz band. The measured radiation gains range from 1.20 to 1.41 dBi at 2.4 GHz band and from 2.25 to 3.44 dBi at 5 GHz band, respectively.

A small internal ceramic chip antenna for IMT-2000 handsets is investigated experimentally and numerically. It has a bandwidth of about 14%, measured gain of 1.3 dBi, and an omnidirectional radiation pattern similar to that of a monopole antenna. These features make the proposed antenna suitable for handset applications.

A modified sleeve monopole type antenna that features a novel broadband technique is demonstrated experimentally and numerically. A bandwidth of 24.2% (|S11| < –20 dB) can be achieved, and an omnidirectional radiation pattern is obtained. The electrical characteristics of the proposed antenna make it attractive for use in mobile handset and repeater applications.