MIMO (Multiple Input Multiple Output) technology has been regarded as a practical approach to increase the wireless channel capacity and reliability. In this technology, the performance of multiple antennas has a significant effect on the MIMO channel capacity. Currently, the MIMO channel capacity is mostly evaluated without accounting for the practical aspects of multiple antennas. Though mult...

Varactor tuned printed planar inverted-F antennas (PIFA) are investigated. The low-profile printed antennas are fabricated together with the layouts of its DC control circuits and other RF/baseband circuit footprints. A surface mounted (SMT) varactor is applied as a frequency-tuning element at the middle of the long radiating arm in PIFA. Passive lumped DC bias circuits are implemented with goo...

A low-cost and portable vector network analyzer (VNA) which covered operating frequency between 1MHz to 3GHz is used for vector reflection coefficient and standing wave ratio (swr) of the various microstrip antennas. This paper presents measurements of various ultra wideband (uwb) microstrip antennas for applications in biomedical field. Selection of antenna is an important key for detection of...

Increasingly stringent design constraints imposed by compact wireless devices for telecommunications, defense, and aerospace systems require the miniaturization of antennas. Unlike most electronic components, which benefi t from decreased size, antennas suffer limitations in gain, effi ciency, system range, and bandwidth when their size is reduced below a quarter-wavelength. The electrical size...

Abstracr We construct simal constellations for differential transmission with multiple basestation antennas. The signals are derived using the theory of fixed-point-free groups and are especially suitable for mobile cellular applications because they do not require the handset to have more than one antenna or to know the time-varying propagation environment. Yet we achieve full transmitter dive...

Abstract—In this paper, an attempt is made to present a theory for the design of handset antennas, which results from the long experience that the authors have in the field of handset antenna design. The proposed theory is based on the well-known skin effect and constructs the antenna using a thin wire model that represent the backbone of the final antenna. The analytical solution for the thin ...

Full-wave electromagnetic solver based on the Transmission Line Matrix Method has been deployed on Grid test-bed. This Grid-based electromagnetic approach exploits the availability of computing node at disposal through the Grid to face the demand of arbitrary large simulations by allocating a corresponding amount of resources hence minimizing the overall elapse time. In order to highlight the b...

An optimized design for the spanner shape regular hexagonal monopole (RHM) patch antennas has been reported to yield ultra wide band (UWB) impedance bandwidth. Impedance and radiation characteristics are presented and discussed. From the results, it has been observed that, the impedance bandwidth, defined by 10 dB return loss, can reach a value of 8.63GHz. A rectangular slit in the radiating pa...

High-gain and low-profile antennas are required for high-speed wireless communication systems and mechanically-scanning automotive radars in the millimeter-wave band. Waveguide antenna is one of the most attractive planar antennas for such millimeter-wave systems because of its low loss and high efficiency characteristics in high frequency band. Travelling-wave excitation is more effective for ...