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This paper presents the design of a broadband circularly polarized microstrip slot antenna fed by a coplanar waveguide. The broadband circular polarization is achieved by projecting an ‘▢’ shaped metallic strip from the ground plane towards the center of the slot. Simulated results show an impedance bandwidth of 32.27%, AR bandwidth of 9.1% and gain of 4.28 dBi. Measured results of fabricated prototype...
In this paper, a compact zeroth-order resonating (ZOR) metamaterial antenna with coplanar waveguide (CPW) feed is presented. The proposed antenna has an impedance bandwidth of 19.82% centered at 3.33 GHz. The proposed structure having smaller electrical size 0.288 λ0 × 0.186 λ0 × 0.018 λ0, where λ0 is the free space wavelength at ZOR mode (at f0 = 3.33 GHz). In addition, antenna offers peak gain of...
In this paper, a zeroth-order resonating circular patch antenna with triangular stub is proposed. The proposed antenna has an electrical size of 0.23λ0 × 0.13λ0 × 0.01λ0 with an impedance bandwidth (|S11| < −10 dB) of 21.4% (resonating frequency 2.8 GHz). Circuit values of proposed equivalent circuit have been extracted using advanced design system to plot dispersion diagram which shows zeroth...
Heterojunction detectors used as free-carrier and intervalence band detectors for a wide wavelength region are presented. Using a well-studied III–V system of GaAs/AlxGa1−xAs to cover a wide wavelength range from UV to far-infrared (THz) is an important development in detector technology. Using the intervalence band (heavy hole, light hole and split off) transitions for high operating temperature...
In this paper a dual-band bandstop filter using tri-section stepped impedance open stub configuration is presented. Transmission zero positions ( i.e stopbands ) can be controlled by tuning the impedances of the shunt tri-section stepped impedance unit and the series transmission line impedance is used to allocate the transmission poles to sharp the attenuation rate. Design equations were derived...
We present the design and fabrication of a bandwidth enhanced metamaterial absorber, based on multiple wires printed on metal backed lossy dielectric substrate. The proposed structure is fabricated using screen printing technique. In the proposed structure, broadband absorption is achieved by overlapping the absorption peaks of individual wires. Results show that bandwidth of proposed absorber corresponding...
A dual-band stub-loaded microstrip reflectarray antenna with microstrip antenna feed is proposed. The 1 × 3, 3 × 1 and plus-shaped reflectarrays have been studied. A parametric study for varying distances between feed patch and the array has also been done. In dual bands, an optimum gain of more than 8 dBi is obtained in plus shaped array configuration.
Future of microwave, power and photonics industry is focused on GaN due to its extraordinary material properties such as wide and direct band gap, large thermal and chemical stability, high breakdown voltage, high saturation velocity. Formation of devices for these applications requires a material selective etching which is performed via wet-etching process. In this paper, temperature dependent etching...
Here in this paper a compact Slow-Wave Substrate Integrated Waveguide (SW-SIW) is presented. The scale reduction is done using the Half-Mode SIW method which reduce the lateral dimension of the SIW into the half, along with the three layer Slow-Wave SIW method presented in a previous research paper. Combining these two methods show that the overall scale of the SIW is significantly reduced without...
La(Sr)MnO3 and La(Ba)MnO3 (LBMO) are fabricated on ZnO for novel p-n junction sensitive to UV light. In-plane orientational growths are clarified. LBMO/ZnO shows huge light amplification of current which indicates phase-related resistive change in LBMO by light.
In this paper we present a steady state analysis of Si-i0.12Ge0.73Sn0.15/Si0.11Ge0.73Sn0.14 transistor laser (TL) with strain-balanced Ge0.85Sn0.15 single quantum well (QW) in the base. Coupled rate equations in the QW region is used to obtain threshold base current density, steady state electron and photon densities. We find that the nature of variation of threshold base current density, steady state...
We have investigated the effects of alloy composition (y) on gain of a Ge1−ySny heterostructure avalanche photodiodes (APDs). The band-offsets become a function of alloy composition and affect the carrier confinement at heterointerfaces. The photocurrent is computed using the composition dependent parameters and, hence, the effect of alloy composition on gain of the APDs have been investigated.
We present a theoretical study of the gain of a CMOS compatible thin submicron Si-CMOS p-i-n avalanche photodetector (APD) suitable for high-speed, low-voltage operation. A 2-D model is used to estimate the avalanche build-up of carriers in the depleted region considering the dead-space effect. The model is also considered the effects of diffusion of carriers from the substrate region. The results...
This paper presents the design and fabrication of an integrated tunable MSM PD based on Indium Tin Oxide (ITO) that is fabricated on Si and InP. Tuning is achieved by thermally controlling the bandgap of the semiconductor using a Nickel Chromium (NiCr) microheater which is collocated on the opposite side of the PD substrate.
A PCF structure that is filled up with chloroform in its core, is optimized for generating broadest possible supercontinuum spectrum which centers at 1310 nm. It has been found that a chloroform filled PCF having airholes of diameter 1.5µm and cladding of pitch 1.2µm is capable producing broadest supercontinuum light at a shorter distance than as silica core PCF can do. The generated supercontinuum...
A novel design of optical comb filter using the effect of periodic chirp and full duty cycle sampling in sampled fiber Bragg grating is proposed and numerically demonstrated. The spectral Talbot phenomenon is realized in the proposed periodically chirped Gaussian-sampled fiber Bragg grating (PC-GSFBG). The channel counts of the filter can be controlled either or both by using FWHM and chirp coefficient...
The design, characterization & fabrication of a uniplanar S band Coplanar Waveguide (CPW) Band Pass Filter has been described in the paper. The filter consists of open stub discontinuities, in series, which act as a resonant circuit, thereby exhibiting a band pass filter response. The paper also discusses about the gradual improvement in the frequency response and roll-off rate of the band pass...
This paper investigates the design of metamaterial (MTM) microstrip patch antennas (MPA) for multiband and wide band applications. The MTM unit cell S-shape loaded reactive impedance surface (S-RIS) is analyzed for square and triangular shape patch antennas. The array of S-RIS unit cell formed metasurface for microstrip patch antenna. It is observed that triangular shape patch gives high bandwidth...
A simple and compact rectangular microstrip antenna with cross headed dumbbell defected patch surface is proposed for noteworthy suppression of cross polarized (XP) radiation, eliminating higher order orthogonal resonance without altering its dominant mode field configuration. The proposed antenna has been studied experimentally with theoretical justifications. More than 28 dB of XP radiation isolation...
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