Soo-Ji Lee

An Eight-Element Compact Low-Profile Planar MIMO Antenna Using LC Resonance with High Isolation

An eight-element compact low-profile multi-input multi-output (MIMO) antenna is proposed for wireless local area network (WLAN) mobile applications. The proposed antenna consists of eight inverted-F antennas with an isolation-enhanced structure. By inserting the isolation-enhanced structure between the antenna elements, the slot and capacitor pair generates additional resonant frequency and decreases mutual coupling between the antenna elements. The overall size of the proposed antenna is only 33 mm× 33 mm, which is integrated into an area of just 0.5 λ× 0.5 λ. The proposed antenna meets 5-GHz WLAN standards with an operation bandwidth of 4.86 - 5.27 GHz and achieves an isolation of approximately 30 dB at 5 GHz. The simulated and measured results for the proposed antenna are presented and compared.

Diffraction by Dielectric-Loaded Multiple Slits in a Conducting Plane: TM Case

A new and exact series solution for the scattering and coupling problems by dielectric-loaded multiple slits in a perfectly conducting screen is presented. The case of normal incidence and TM polarization is considered. The scattered and transmitted flelds are represented in terms of an inflnite series of radial modes. By applying the appropriate boundary conditions, the coe-cients of scattered and transmitted flelds are obtained and some numerical results are given.

Scattering from concave conducting wedges with longitudinal corrugations: TM case

An exact series solution for the scattering from a concaved wedge with longitudinal corrugations is formulated for TM plane wave using the radial mode-matching technique. The scattered and guided fields are represented in terms of an infinite series of radial modes with unknown coefficients. By applying the appropriate boundary conditions, the coefficients of the scattered field are obtained. The diffraction coefficient of a concaved wedge with longitudinal corrugations is subsequently derived from the scattered field.

TE Scattering From Concaved Wedges With Longitudinal Corrugations

An exact series solution for the oblique scattering from a corrugated wedge with concaved edge is formulated for TE plane wave using the radial mode matching technique. The scattered and guided fields are represented in terms of an infinite series of radial modes with unknown coefficients. By applying the appropriate boundary conditions, the coefficients of the scattered field are obtained. The diffraction coefficient of a corrugated wedge is subsequently derived from the scattered field.

Hybrid Power Combining Rectenna Array for Wide Incident Angle Coverage in RF Energy Transfer

This paper discusses a new design approach that uses hybrid power combining rectenna array in radio frequency (RF) energy transfer systems to receive more energy in a wide incident angle range. A beam-forming matrix and a dc power management network (PMN) are introduced to the hybrid power combining. The normalized dc output power of the proposed hybrid power combining array is compared to the conventional power combining methods with regard to the incident wave angle, and the average received dc power is also calculated and compared. To experimentally verify the proposed hybrid combining array performance, four suspended patch antennas are attached to RF energy receiving architecture. A

Compact polarization diversity antenna using a pair of parallel dipoles for mobile RFID

4 \times 4

Electromagnetic scattering from both finite semi-circular channels and bosses in a conducting plane: TM case

Butler matrix and quadrature hybrids are used for the beam-forming matrix in a hybrid power combining rectenna array. A reconfigurable voltage doubler rectifier with a dc PMN is used to convert RF energy to dc energy and delivers proper voltage to the load. The measured results of each component are presented. Moreover, an experimental verification using fabricated components for RF energy transfer is presented and the measured received dc output power of conventional and proposed structures is presented and compared.

Polarization modulation RF power transport for sensor network

A novel compact polarization diversity antenna using a pair of parallel dipoles for mobile UHF radio frequency identification (RFID) is presented. The antenna is composed of a pair of parallel dipoles orthogonally placed on the feeding network. Compare to half wavelength conventional dipole antenna, the overall size of this antenna is less than quarter wavelength. With the compact and simple feeding network below the parallel dipoles, the proposed antenna can generate vertical linear polarization and horizontal linear polarization. The use of the proposed polarization diversity antenna may lead to the higher detection of capability of RFID tags, thus providing the stable and reliable RFID services. Antenna peak gain is 2.05 dBi, and isolation between the two input ports is less than -18dB. Details of the antenna design are shown, and the measurement and simulation results are also provided to validate the proposed idea.

Electronically controlled 2 by 1 arrayed beam forming antenna for UHF RFID reader

The behavior of TM-wave scattering from both semi-circular channels and bosses in a conducting plane is investigated. The scattered field is represented in terms of an infinite series of radial modes with unknown coefficients. By applying separation of variables and employing the partial orthogonality of sine functions, the unknown coefficients are obtained. The boundary conditions are checked for semi-circular channels and bosses to verify the algorithm proposed. Plotted results for the radar cross sections reveal how the scattering properties may be varied by changing several physical and geometrical parameters of the structures.

Slot antenna and information terminal apparatus using the same

As the interest in Internet of Things (IoT) has increased, supplying power to sensor nodes and sensor actuator has emerged to a key problem. To solve the issue, an active study of activating sensor nodes by receiving power from a specific power source wirelessly has been on progress. In particular, transmitting and receiving RF power seems to be the prime power transport technique to realize the next generation internet. In order to transmit and receive power efficiently, the polarization direction of both transmit and receive antenna should be the same. Since the receive antenna of the sensor nodes may have a random polarization direction depending on its installation, the transmit antenna should be able to change its polarization for uniform operation of every sensors in a sensor network without any failure. For this need, this paper suggests a modulation technique and a transmit antenna system which can generate 4 types(vertical (90°), horizontal (0°), 45°, 135°) of linear polarization.