The LQG controllers significantly improve antenna tracking precision, but their tuning is a trial-and-error process. A control engineer has two tools to tune an LQG controller: the choice of coordinate system of the controller, and the selection of weights of the LQG performance index. The paper selects the coordinates of the open-loop model that simplify the shaping of the closed-loop performa...

A printed circular open-loop antenna is introduced as a simple structure for producing circular polarization, the antenna is fed with a coaxial probe. By introducing a gap within the circular loop a traveling-wave current is excited and thus circularly polarized radiation can be achieved. An optimized circularly polarized antenna is designed through numerical analysis using a so-called parametr...

This paper presents a multiband folded loop antenna for smart phone applications. The proposed antenna with a symmetric loop pattern generates four resonance modes in the design bands. The current distributions of the excited resonance modes are analyzed to confirm the mode characteristic. Using a pair of tuning elements near the feed port, the impedance bandwidth is broadened to cover GSM850/G...

This paper presents a one-wavelength loop antenna fed by an inductively coupled loop for on-body applications. An equivalent circuit for the inductively coupled loop antenna is proposed to synthesize the antenna system with a microchip. The designed tag is printed on a PVC substrate and placed close to a four-layer stratified elliptical cylinder human model. The card-type tag measures 85.5 × 54...

A segmented loop antenna is presented for ultra-high frequency (UHF) near-field radio frequency identification (RFID) applications. The proposed segmented configuration makes the current along the loop remain in-phase even though the perimeter of the loop is comparable to the operating wavelength, so that a strong and uniform magnetic field is generated in the region surrounding the antenna. Th...

─ A novel loop-loaded printed dipole (LLPD) with a wideband balun structure is presented for aiming a dual-band antenna operation at 3.0/5.5 GHz bands. The proposed balun structure alone demonstrates VSWR<1.5 performance over a 3:1 bandwidth. As the loop elements placed on the antenna aperture provides dual-band operation with at least 15% impedance bandwidths, the wideband balun/feed allows fo...

In this paper, we will introduce a cocentered orthogonal loop and dipole antenna (COLD) to a borehole radar system. With the cocentered orthogonal loop and dipole antenna, we could obtain additional information on polarization state of arrival waves in the borehole radar using * optical modulators. We set the proposed antenna in a borehole actually, and made electromagnetic waves with known pol...

In recent years, many small internal antennas have been designed for mobile handsets in [1, 2]. Many monopole-type antennas have been investigated because they operate at the lowest resonant mode which is helps to reduce their size. A loop-type antenna, on the other hand, has rarely been applied to small antenna design because the lowest resonant mode is a parallel resonance (anti-resonance). C...

Artificial Neural Network (ANN)s are best suited for prediction and optimization problems. Trained ANNs have found wide spread acceptance in several antenna design systems. Four parameters namely antenna radiation resistance, loss resistance, efficiency, and inductance can be used to design an antenna layout though there are several other parameters available. An ANN can be trained to provide t...

In this paper requirements for the Ultra-wideband antenna and differences between narrow-band and ultrawideband antennas for wireless system are discussed. Also a novel printed loop antenna with introducing an L shape portion to its arm is presented. The antenna offers excellent performance for lower-band frequency of UWB system, ranging from 3.1 GHz to 5.1 GHz. The antenna exhibits a 10 dB ret...