A novel reconfigurable microstrip antenna with switchable polarization sense is proposed. The proposed has a simple structure, consisting of corner-truncated square radiating patch, four small triangular conductors, and line feed. Using independently biased PIN diodes on the it can produce linear polarization, or left- right-hand circular according to bias voltages. From measured results, low cross-polarization levels when operated in state good axial ratios are observed.

In this letter, a defected ground structure (DGS) is applied to design compact microstrip rat-race hybrid coupler. The proposed can achieve both significant reduction of size and harmonic signal. By embedding the DGS section, it observed that resonant frequency coupler significantly lowered, which lead large amount for fixed operation. Besides, third signal suppressed -30 dB with respect conventional case, measured insertion loss comparable

A printed wide-slot antenna with a parasitic patch for bandwidth enhancement is proposed and experimentally investigated. simple 50-Ω microstrip line used to excite the slot. rotated square slot resonator considered as reference geometry. The exhibits two resonances (f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> : lower resonant frequency, f xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> higher frequency). By embedding into...

A microstrip patch antenna using a defected ground structure (DGS) to suppress higher order harmonics is presented. An H-shaped defect on the plane with only one or more unit lattices has been utilized and yielded bandstop characteristics. Compared conventional without DGS cell, radiated power of at harmonic frequencies drastically decreased.

A printed microstrip-fed monopole ultra-wideband (UWB) antenna with triple notched bands is presented. By embedding a modified H-shaped resonator an additional outer line beside the microstrip feedline, band-rejected filtering properties around 3.5 GHz WiMAX band, 5.2/5.8 WLAN and X-band satellite communication band are generated. The frequencies can be adjusted according to specification by altering resonator. Sharp gain reductions occur at 3.7, 5.2, 7.5, 7.9 GHz. However, for other outside...

A reconfigurable antenna using two PIN diodes is presented for quad-band (GSM900/GSM1800/GSM1900/UMTS) mobile handset applications. The proposed has a size of 45 × 11×6mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> . By independently adjusting the on/off states located on radiating element, structure can be operated in PIFA and loop mode, respectively. are replaced by conducting tape order to verify concept. In regards fabricated...

In this letter, a novel polarization-reconfigurable antenna with T-shaped feed is proposed. This mainly comprises square patch, feed, two p-i-n diodes, conductive pads via hole, and ring slot in ground plane. The diodes hole are used to switch the polarization mode of antenna. Each branch line connected or disconnected from plane through by independently adjusting bias states diodes. As result, proposed exhibits either right-hand circular (CP) left-hand CP when only one on state. On other...

Microstrip antennas inherently have a high input impedance at resonant frequency. This may not be convenient for some applications. For active integrated antennas, moreover, the radiated power of microstrip needs to very low harmonic frequencies. The main goals this study are matching and suppression antennas. In order meet these requirements, two one-dimensional (1-D) photonic bandgap (PBG) structures, namely, defected ground structure (DGS) compact cell (CMRC), applied feed line...

A novel design of patch antennas with polarization diversity is proposed and experimentally studied in this letter. pair L-type slits embedded into the edge square shape slit changed according to on- or off-state PIN diode. Therefore, antenna has different polarizations. The structure we describe here enables optimization input match for both From measured result, low cross-polarization levels linear state good axial ratios circular are observed.

In this letter, a novel ultrawideband (UWB) antenna with dual sharply rejected notch bands is proposed. The proposed consists of circular-shaped radiating element, 50microstrip feed line, two short-circuited folded stepped impedance resonators (SIRs), and partially truncated ground plane. compact SIRs are located beside the line to achieve band rejection characteristic. shows UWB characteristics from around 3.07 up 10.61 GHz for VSWR<;2 one frequency at 3.41~3.68 other 5.37~6.01 GHz. notched...

In this study, a dual-feed polarization diversity antenna with broadside or conical radiation pattern is proposed. the proposed structure, radiator designed based on circular slot and separated into two semi-circular slots using protruding stub. Different patterns can be implemented in same frequency band by adjusting phase difference applied to slots. A modified 90° branch coupler was used as feed structure. Analysis of current E-field distributions confirmed that there between according...

We investigated characteristics of high performance GaN-based laser diodes grown on LEO-GaN/sapphire and free-standing GaN substrates. The maximum output power was 300 mW under cw operation. operation current voltage were 53 mA 4.67 V, respectively, for 30 mW-output power. Thermal simulation junction temperature measurement showed that epi-down bonding essential the use sapphire substrate. It proposed Mg diffusion into active layers responsible degradation mechanism diodes. (© 2004 WILEY-VCH...

A novel design is described for a dual-band circularly polarized pentagonal slot antenna. The circular polarization (CP) radiation characteristics are achieved by loading with proper asymmetry, which placed at the opposite angle of feed line. prototype proposed implemented and measured. Measured results show that patterns good CP obtained two resonant frequencies.

In this letter, a novel monopole antenna for USB dongle applications is proposed. It composed of and an inverted U-shaped parasitic radiator. The acts as feeding structure in the 2.4-GHz band while serving main radiator 5.5-GHz band. By properly combining resonance ground resonance, proposed has wide bandwidth at f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> . Also, xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> easily achieved...

In this letter, a reconfigurable rhombus-shaped patch antenna with Y-shaped feedline for polarization diversity is proposed. This exhibits simple structure, which consists of patch, two p-i-n diodes, and feedline. The diodes are inserted in the gap between order to easily supply dc bias voltage shorting pin center patch. proposed can be operated modes-the left-hand circular (LHCP) right-hand (RHCP) modes-by electrically controlling diodes. measured 10-dB reflection coefficient 3-dB...

In this letter, a novel dual-band and polarization-flexible substrate integrated waveguide (SIW) cavity antenna is proposed. The SIW used for the excited by conventional <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\rm TE}_{120}$</tex> </formula> mode its first resonance. With intervention of slot, second resonance modified- also generated, thereby providing broadside radiation pattern at two...

A single-feed equilateral-triangular microstrip antenna has been designed with truncated corners for diverse radiation polarizations. The proposed is excited by a line placed parallel to the oblique side of an patch. exhibits linear polarization (LP), left-hand circular polarization, or right-hand (RHCP) depending on whether three identically sized triangular patch are cut. novel reconfigurable selectable based this first antenna. This second simple structure consisting corner-truncated...

We demonstrated the long wavelength (485nm) lasing of InGaN laser diodes under continuous wave condition at room temperature over 10mW. Two structures were adapted with different indium composition for optical confinement layers (OCLs) below quantum wells. The blue shift electroluminescence (EL) was reduced in grown on 3% In concentration OCL compared 1.5% OCL. EL peak diode occurs longer all current levels to addition, laterally nonuniform wells verified by cross-sectional view active layer...

A novel approach for designing dual-mode dual-band bandpass filters is proposed and experimentally studied. By embedding a pair of slits in the square patch, response realized one transmission zero introduced between two passbands. Two degenerate modes are achieved by loading with small perturbation, which can be placed at diagonal line. There three zeros. The control first third On other hand, right crossed slots second

A printed wide-slot antenna for wideband applications is proposed and experimentally investigated in this communication. modified L-shaped microstrip line used to excite the square slot. It consists of a horizontal line, patch, vertical line. For comparison, simple feed structure with same width as reference geometry. The exhibits dual resonance (lower resonant frequency <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</i> <sub...

The authors report on the high-performance blue laser diodes (LDs) with an emission wavelength of ~448 nm employing InGaN single-quantum-well (QW) active layers. At 100-mW continuous-wave (CW) output power, operation current and voltage are, respectively, 150 mA 5.3 V, corresponding to wall plug efficiency >12%, a record value for single-mode LDs wavelengths. single QW LD showed normal temperature dependence light output-current curves characteristic 170 K. In addition, we demonstrate high...

In this letter, a reconfigurable antenna for mobile handset applications is proposed. This mainly consists of longer strip, shorter and p-i-n diode. Coupling generated at the gap between strip strip. Depending on different states diode, degree coupling them controlled, fundamental resonant frequency proposed adjusted. As result, in low band covers LTE700/GSM850/900 bands. The high formed by combining higher-order mode quarter-wavelength to cover GSM1800/1900/UMTS/LTE2300/2500

In this letter, a dual-feed circularly polarized slot antenna with polarization diversity is proposed. The proposed consists of circular that acts as radiator, dual-microstrip line feeding structure, slit applied to ground plane (GND), and protruded stub. (CP) easily obtained by protruding stub because it perturbation in slots. good isolation between two ports achieved the plane. From measured results, CP operating bandwidth 22.4%. less than −15 dB within bandwidth.