Sultan Shoaib

Design and Performance Study of a Dual-Element Multiband Printed Monopole Antenna Array for MIMO Terminals

This letter presents a study on linearly polarized compact multiband multiple-input-multiple-output (MIMO) antenna system for small mobile terminals. The MIMO antenna system consists of two symmetric printed monopole antennas with edge-to-edge separation of 0.097 λ0 at 900 MHz. Each antenna element has a capacitive feed and is composed of two twisted lines, a parasitic loop, and a shorting trip that generate five resonant modes around 900, 1800, 2100, 3500, and 5400 MHz, covering GSM850/900, DCS, PCS, UMTS, WLAN, and WiMAX frequency bands. Two inverted-L shaped branches and a rectangular slot with one circular end, etched on the ground plane, were introduced to improve the isolation between antenna elements. The isolation achieved is higher than 15 dB in the lower band and 20 dB in the upper bands, leading to an envelope correlation coefficient of less than 0.025. The simulated performance of the designed antenna system has been verified in the experiment.

MIMO Antennas for Mobile Handsets

In this paper, two multiband MIMO antennas for mobile handsets are proposed. The first antenna is capable of covering GSM900, GSM1800, GSM1900, and UMTS. It has two loop type antenna elements, which are with the same structures and dimensions. The dimensions of the antenna element is 22.5*25mm2. Two structures which are slot and inverted-L branches on the ground, are used to minimize the mature coupling between the two antenna elements. The second antenna can cover GSM1800, GSM1900, UMTS, WLAN and LTE frequency bands. The presented antenna consist of two coupled fed monopole antennas that are oriented diagonally at the non-grounded portion of the circuit board. Two decoupling structures are etched diagonally on the bottom layer of the circuit board to improve the isolation between the two antenna elements. Both of simulation and measurement results are shown to illustrate the performance of the proposed two MIMO antennas.

Compact and printed MIMO antennas for 2G/3G and 4G — LTE mobile tablets

This paper presents four meandered MIMO antennas printed in symmetric configuration on top and bottom no-ground edges of the substrate. Two of the four MIMO antennas are coupled fed monopoles covering GSM 900/GSM 1800/1900, UMTS and WLAN frequencies whereas, the other two MIMO antennas are direct fed monopoles covering LTE 700 and WLAN 2.45 GHz. The substrate used is FR-4 with relative permittivity of 4.35 and an overall volume of 230 × 176 × 0.8 mm3. Each antenna covers an area of approximately 75 × 50 mm2. The decoupling technique used in the design involves four ground slots and two coupled ground extensions. The isolation performance of the MIMO antennas is better than 15 dB over all the cellular bands covered by the antennas. The simulated and measured results substantiate a good performance of the MIMO antennas.

Compact and printed multiband antennas for 2G/3G/4G smartphones

This paper presents a compact multiband antenna system for mobile handsets capable of covering 2G, 3G and 4G cellular frequency bands. The antenna system is composed of two antennas that are etched diagonally on the non-grounded portion of the substrate board. The substrate board used is FR-4, of relative permittivity 4.35 and loss tangent of 0.02, with overall dimensions of 136 × 70 × 0.8 mm3. The antenna for covering 4G and WLAN frequency bands is a direct fed printed monopole antenna whereas, the antenna for covering the 2G and 3G cellular services is a coupled fed monopole antenna. Two inverted-L shaped metallic extensions, etched on the bottom layer of the substrate, were introduced to improve the isolation between antennas. The isolation achieved is better than 16 dB in the lower band and 22 dB in the upper bands, leading to an envelope correlation coefficient of less than 0.251. The simulated and measured results corroborate a good performance of the proposed antenna system.

Uncertainty analysis of circular iris waveguide verification standard for vector network analyzers

This paper presents the uncertainty analysis of circular iris waveguide verification standard for the vector network analyzer measurements at millimeter frequencies. In particular, the uncertainty contributions due to the fabrication process of circular waveguide in the iris section are discussed. The work involves the standard uncertainty computation for transmission scattering parameter (S-parameter) of the circular iris section in WR-03 waveguide size.

Increasing the Effective Range of Smart Meter Home Area Network

In this letter, we present a potential novel solution to increase the transmission range of the home energy network of electricity smart meters. Conventionally, smart meters use low-power radio technologies and suffer from high signal attenuation as the signal is propagated through multiple radio-absorbing walls in a property. This limits the range of the radio link between the meter and connected devices, such as communications hubs, smart appliances, and in-hand displays. The potential solution presented in this letter uses the observation that at high microwave frequencies, the ac mains distribution cables can act as a low-loss ‘‘leaky feeder’’ cable so enabling signal to be distributed to each room more efficiently than directly via through the air. This letter reports on the testing of this concept for the first time in five properties of various construction types. The results demonstrate a good validity of the proposed method.

MIMO antennas for mobile handsets

This letter presents a pair of printed MIMO antennas for mobile handsets. With each antenna being a coupled fed monopole in a meandered shape, it is capable of covering GSM 1800/1900, UMTS, WLAN, and LTE frequency bands. The antennas are oriented diagonally at the nongrounded portion of the circuit board. The substrate used for the circuit board is FR4 with relative permittivity of 4.4 and loss tangent of 0.02. The overall volume of the circuit board is 110×65×0.8 mm3, with each antenna occupying an area of 24×14.5 mm2. To improve the isolation between antennas, dual decoupling structures consisting of ground slots and inverted L ground branches that extend into the nongrounded portion are etched diagonally on the bottom layer of the substrate. The isolation achieved is better than 15 dB over all the frequency bands covered by each antenna leading to an envelope correlation coefficient of less than 0.02. The simulation and measured results are in good agreement.