Compact Bandstop Filters with Extended Upper Passbands

This paper presents new compact bandstop filters (BSFs) with extended upper passbands. In the basic proposed filter configuration, the conventional quarter-wavelength open-stub resonators are replaced with equivalent two-section stepped impedance resonators. Transmission line analysis is used to determine the dimensions of the equivalent stepped impedance sections. The filter structure is analyzed using a full wave electromagnetic (EM) simulator and then realized at 2.3 GHz band. Experiments have also been done to validate the performance of the design concept. Compared with the conventional quarter-wavelength-based bandstop filter, significant extensions of the upper passband beyond 9 GHz and 40% size reduction are achieved. Two other variations of the proposed basic BSF with further size reduction (more than 60%) are implemented and their measured performances are verified

Millimeter Wave Antenna with Mounted Horn Integrated on FR4 for 60 GHz Gbps Communication Systems

A compact high gain and wideband millimeter wave (MMW) antenna for 60 GHz communication systems is presented. The proposed antenna consists of a multilayer structure with an aperture coupled microstrip patch and a surface mounted horn integrated on FR4 substrate. The proposed antenna contributes impedance bandwidth of 8.3% (57.4–62.4 GHz). The overall antenna gain and directivity are about 11.65 dBi and 12.51 dBi, which make it suitable for MMW applications and short-range communications. The proposed antenna occupies an area of 7.14 mm × 7.14 mm × 4 mm. The estimated efficiency is 82%. The proposed antenna finds application in V-band communication systems

High Gain and High Efficient Stacked Antenna Array with Integrated Horn for 60 GHz Communication Systems

In order to achieve wide bandwidth and high gain, we propose a stacked antenna structure having a microstrip aperture coupled feeding technique with a mounted Horn integrated on it. With optimized parameters, the single antenna element at a center frequency of 60 GHz, exhibits a wide impedance bandwidth of about 10.58% (58.9–65.25 GHz) with a gain and efficiency of 11.78 dB and 88%, respectively. For improving the gain, we designed a 2 × 2 and 4 × 4 arrays with a corporate feed network. The side lobe levels were minimized and the back radiations were reduced by making use of a reflector at λ/4 distance from the corporate feed network. The 2×2 array structure resulted in improved gain of 15.3 dB with efficiency of 83%, while the 4×4 array structure provided further gain improvement of 18.07 dB with 68.3% efficiency. The proposed design is modelled in CST Microwave Studio. The results are verified using HFSS, which are found to be in good agreement

A DR Loaded Substrate Integrated Waveguide Antenna for 60 GHz High Speed Wireless Communication Systems

The concept of substrate integrated waveguide (SIW) technology along with dielectric resonators (DR) is used to design antenna/array for 60 GHz communication systems. SIW is created in the substrate of RT/duroid 5880 having relative permittivity εr=2.23 and loss tangent tan⁡δ=0.003. H-shaped longitudinal slot is engraved at the top metal layer of the substrate. Two pieces of the DR are placed on the slot without any air gap. The antenna structures are modeled using CST Microwave Studio and then the results are verified using another simulation software HFSS. Simulation results of the two designs are presented; first a single antenna element and then to enhance the gain of the system a broadside array of 1×4 is presented in the second design. For the single antenna element, the impedance bandwidth is 10.33% having a gain up to 5.5 dBi. Whereas in an array of 1×4 elements, the impedance bandwidth is found to be 10.70% with a gain up to 11.20 dBi. For the single antenna element and 1×4 antenna array, the simulated radiation efficiency is found to be 81% and 78%, respectively

Fabrication and Characterization of a W-Band Cylindrical Dielectric Resonator Antenna-Coupled Niobium Microbolometer

We report on the fabrication and characterization of a novel antenna-coupled detector configuration for detection at 94 GHz, a coplanar waveguide- (CPW-) fed, slot-excited twin dielectric resonator antenna- (DRA-) coupled niobium (Nb) microbolometer. The antenna is based on two low permittivity cylindrical dielectric resonators (CDRs) excited by rectangular slots placed below the CDRs. The antenna resonant currents are fed to an Nb microbolometer by the means of a CPW feed. The ceramic DRA structure is manufactured using a novel fabrication process that enables patterning an SU-8–Alumina (Al2O3) nanopowder composite using conventional photolithography. The detector measured a voltage responsivity of 0.181 V/W at a modulation frequency of 150 Hz. The detector measured a time constant of 1.94 μs. The antenna radiation pattern of the developed detector configuration was measured and shows a good agreement with the simulation

Electromagnetic scattering from chiral cylinders of arbitrary cross section

In this dissertation, the problem of electromagnetic scattering from a chiral cylinder of arbitrary cross section has been formulated using the surface equivalence principle and then solved numerically using the method of moments. The Green\u27s dyads for chiral media are used to develop explicit expressions for the coupled copolarized and crosspolarized electric fields produced by two-dimensional electric and magnetic current distributions in an unbounded chiral medium. The surface equivalence principle is used to replace the chiral cylinder by equivalent electric and magnetic surface currents radiating in unbounded media. A set of coupled integral equations is obtained by enforcing the boundary conditions on the tangential components of the total electric field. The resulting surface E-field integral equations are solved by the method of moments with point matching and pulses as expansion functions. The problems which are considered in this research include both TM\sb{\rm z} and/or TE\sb{\rm z} plane wave incidence. Numerical results, including echo widths and internal fields for several chiral cylinders of different parameters are found and reported in this dissertation. The numerically obtained data are in excellent agreement with the exact data found by the eigenfunction solution for the circular chiral cylinder. The effect of adding chirality to the scatterers is investigated throughout the numerical results of several chiral cylinders of different shapes and material parameters. The results demonstrate the feasibility of the employment of chirality in applications such as to control the radar cross section (RCS) of scatterers and in the synthesis of anti-reflection composite materials. It is also observed that although the effect of chirality on RCS is noticeable, it is not predictable by a simple theory. The method developed in this dissertation to treat scattering from chiral cylinders of arbitrary cross section can be easily extended to address problems of scattering by two-dimensional chiral radomes and by chiral-covered conducting cylinders. The method can, also, be extended to three-dimensional chiral objects of arbitrary shape. The advantages and limitations of the method are briefly discussed

BCB-Si Based Wide Band Millimeter Wave Antenna Fed by Substrate Integrated Waveguide

A benzocyclobutene (BCB) silicon (Si) based wideband antenna for millimeter wave applications is presented. The antenna consists of multilayer with one layer of BCB and the remaining three layers of Si. A patch is etched on the Si substrate above the air gap, which is excited through a slot. This architecture of slot, air gap, and patch will produce wide bandwidth by merging each one of resonances. The simulated results show that the antenna provides an 11 < −10 dB bandwidth of 9.7 GHz (17%) starting from 51.5 GHz to 61.2 GHz around 57 GHz central frequency. The antenna provides a maximum gain of 8.9 dBi with an efficiency of 70%