Zhe-Feng Yu

Differential microfluidic sensor on printed circuit board for biological cells analysis

Coulter principal based resistive pulse sensor has been demonstrated as an important platform in biological cell detection and enumeration since several decades ago. Recently, the miniaturized micro‐Coulter counter has attracted much attention due to its advantages in point of care diagnostics for on chip detection and enumeration of rare cells, such as circulating tumor cells. In this paper, we present a microfluidic cytometer with differential amplifier based on Coulter principle on a SU‐8 coated printed circuit board substrate. The electrical current changes induced by the blockage of the microparticles in the sensing aperture are calibrated by polystyrene particles of standard size. Finally, HeLa cells are used to evaluate the performance of the proposed device for enumeration of biological samples. The proposed cytometer is built upon the cheap and widely available printed circuit board substrate and shows its great potential as personalized healthcare monitor.

Reconfigurable Loop Antenna With Two Parasitic Grounded Strips for WWAN/LTE Unbroken-Metal-Rimmed Smartphones

A reconfigurable loop antenna with two parasitic grounded strips for modern smartphone devices is presented in this paper. The most essential merit of this proposed reconfigurable antenna is that it can keep the intactness of the outer metal rim. In addition, it can generate multiantenna modes. The outer metal rim generates three loop modes and the inner parasite grounded strips can provide two monopole modes. By merging these two types of antenna modes, it can offer two wide bandwidths to cover GSM850/900, DCS/PCS/UMTS2100, and LTE2300/2500 operations with a compact antenna size of 945 mm2. The detailed operating principles and design considerations of this proposed reconfigurable antenna are described. In order to validate this proposed antenna, it was fabricated and tested. The measured antenna efficiencies and gains are satisfied with the requirements for the modern communication devices.

SIW Butler Matrix with Modified Hybrid Coupler for Slot Antenna Array

This paper presents a substrate integrated waveguide Butler matrix with a modified hybrid coupler, operating from 28 to 32 GHz. The modified hybrid coupler is realized by using 90° hybrid coupler followed by a −45° compensating phase shifter. Thus, 45°/135° output phase differences can be obtained using this type of coupler. Compared with the equal-length unequal-width phase shifter, the compensating phase shifter exhibits better phase characteristics, with only 3° phase error over 28–32 GHz. Because the phase of compensating phase shifter is not realized by taking the phase introduced by the crossover as a reference, it gives great flexibility to the design of compensating phase shifter. Adopting the modified hybrid coupler, the designed Butler matrix features the output phases with peak to peak error of 13° and wideband performance from 28 to 32 GHz. The slot array fed by the Butler matrix can radiate four slanted beams with acceptable measured gains, in the range of 9.7~12 dBi for port 1 excitation and 8.4~11.1 dBi for port 2 excitation. The radiated beams can reach a wide azimuthal coverage between ±61°.

Tri-Polarized 12-Antenna MIMO Array for Future 5G Smartphone Applications

A tri-polarized 12-antenna array working in the 3.5-GHz band (3.4–3.6 GHz) for future 5G (the fifth generation mobile communication) multiple-input multiple-output (MIMO) operations in the smartphone is presented. In order to reduce the mutual couplings and simplify the design process, orthogonal polarization technique is utilized. By combining a quarter mode substrate integrated wave-guide antenna and two open-end slots, a compact 3-antenna tri-polarization block operating in the 3.5-GHz band is achieved within a small volume of <inline-formula> <tex-math notation=LaTeX>

Planar Millimeter-Wave 2-D Beam-Scanning Multibeam Array Antenna Fed by Compact SIW Beam-Forming Network

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Miniaturized Dual-Loop NFC Antenna With a Very Small Slot Clearance for Metal-Cover Smartphone Applications

</tex-math></inline-formula> mm³. Thanks to the orthogonal polarization features, the three antennas within the block are able to have good impedance matchings and low mutual couplings between antennas. By integrating four such tri-polarization blocks, a 12-antenna MIMO array is then designed for smartphone applications. It is also due to the tri-polarization feature, the proposed array could attain acceptable isolations and low correlations between antennas with only two additional decoupling structures. The proposed array is fabricated and tested, good antenna performances, such as return loss better than 10 dB, isolation higher than 12.5 dB, and antenna efficiencies higher than 50%, are obtained. The channel capacity of the 12-antenna array is calculated to be about 57 bps/Hz in a <inline-formula> <tex-math notation=LaTeX>

NFC Loop Antenna in Conjunction With the Lower Section of a Metal Cover

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Miniaturized SIW Multibeam Antenna Array Fed by Dual-Layer 8 × 8 Butler Matrix

</tex-math></inline-formula> MIMO system with 20-dB signal-to-noise ratio, which indicates the proposed array using tri-polarization technique is a good choice for future 5G terminals.

Eight-port orthogonally dual-polarised MIMO antennas using loop structures for 5G smartphone

A planar millimeter-wave 2-D beam-scanning multibeam array antenna fed by compact 16-way beam-forming network (BFN) in multilayered substrate integrated waveguide (SIW) technology is addressed. The BFN is formed by connecting two stacks of sub-BFNs, the E-plane sub-BFN and the H-plane sub-BFN. The H-plane sub-BFN is realized by a traditional H-plane <inline-formula> <tex-math notation=LaTeX>

Four-feed reconfigurable MIMO antenna for metal-frame smartphone applications

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