scholarly journals Broadband Waveguide Feed for Parabolic Reflectors

1994 ◽  
Vol 17 (1) ◽  
pp. 9-19 ◽  
Author(s):  
P. Bhushan Mital
Keyword(s):  
Wide Band ◽  
Design And Development ◽  
Parabolic Reflector ◽  
Waveguide Components ◽  
Rectangular Waveguides ◽  
Parabolic Reflectors ◽  
Ridged Waveguide ◽  
Good Agreement ◽  
Horn Feed

The broadband requirement in microwave systems has necessitated attention on components that can operate over frequency ranges far broader than those of standard rectangular waveguides. This paper describes the design and development of an ridged horn to match the waveguide impedance to freespace impedance so that the horn could be used as a feed for an offset-fed parabolic reflector over a wide band of frequencies, i.e., C and X bands (4.2 to 10.2 GHZ). In the present case, a five stepped chebyshev transformer has been used. Complete design required for horn feed as well for the ridged waveguide components necessary for testing has been carried out. The results obtained are quite encouraging. Good agreement is found between the measured results and theoretical values.

scholarly journals Micromachining and Characterisation of Folded Waveguide Structure at 0.22THz

2021 ◽  
Author(s):  
Rakesh Kumar Bhardwaj ◽  
H. S. Sudhamani ◽  
V. P. Dutta ◽  
Naresh Bhatnagar
Keyword(s):  
Wireless Communication ◽  
High Speed ◽  
Wireless Systems ◽  
Wide Band ◽  
Folded Waveguide ◽  
Waveguide Components ◽  
Rectangular Waveguides ◽  
Near Future ◽  
Compact Sources ◽  
Conventional Machining

AbstractThe demand of high-speed wireless communication has increased, which need the data rate to be in the order of Terabyte per second (Tbps) in the near future. Terahertz (THz) band communication is a key wireless communication technology to satisfy this future demand. This would also reduce the spectrum scarcity and capacity limitation of current wireless systems. Microfabricated Folded Waveguide TWTs are the potential compact sources of wide band and high-power terahertz radiation. This study primarily focuses on machining technology for THz waveguide components requiring ultra-high precision micromachining. Rectangular waveguides, especially Folded Waveguides (FW), are even more difficult to manufacture using conventional machining techniques due to their small size and very tight tolerances. The criticalities in micromachining of FW for 0.22 THz have been addressed in this article. Half hard free cutting Brass IS 319-H2 was used as a work material due to its electrical and mechanical properties. Waveguide size of 0.852 × 0.12 mm was machined within ± 3–5 μm linear tolerances, surface roughness in the order of 45 nm Ra, and flatness less than half of wavelength (< λ/2). The split top and bottom blocks of the folded waveguide were aligned by dowel pins which matched within a tolerance of ± 5 μm. The perpendicularity and parallelism were maintained within 5 μm tolerance. This work explored and established the application of micromilling as reasonably suitable for the THz waveguides followed by ultrasonic cleaning as deburring. It also investigated the measured folded waveguide losses which were close to simulated values.

scholarly journals Design and Development of Inverted U-Slot Rectangular Ring Coupled Monopole Microstrip Antenna for Quad Band Operation

2021 ◽  
Vol 9 (12) ◽  
pp. 1394-1397
Keyword(s):  
Microstrip Antenna ◽  
Return Loss ◽  
Wide Band ◽  
Microwave Frequency ◽  
Microstrip Antennas ◽  
Frequency Range ◽  
Design And Development ◽  
Directional Radiation ◽  
Novel Design ◽  
Good Agreement

Abstract: This paper present a novel design and development of inverted U-slot rectangular ring coupled monopole microstrip antenna (IURCMMA) for quad band operation. The monopole microstrip antennas are commonly designed for wide band operation. However, by placing the optimum ring slots in the form of slits on the radiating patch, the antenna can be made to operate at different frequency bands. The proposed antenna operates in the frequency range of 1.5 to 10 GHz with a peak gain of 8.69 dB and gives omni directional radiation pattern in both E and H planes. The measured and simulated results of return loss are in good agreement with each other. With these features the proposed antenna may find many applications at microwave frequency range. Keywords: Monopole, Rectangular, Bandwidth, Quad band , Gain.

Design and Development of Ferroelectric Tunable Coplanar Waveguide Components for Ku- and K-Band Applications

2002 ◽  
Vol 42 (1) ◽  
pp. 151-163 ◽  
Author(s):  
Guru Subramanyam ◽  
Nazme Mohsina ◽  
Abdullah Zaman ◽  
Fred W. Van Keuls ◽  
Felix A. Miranda ◽  
...  
Keyword(s):  
Coplanar Waveguide ◽  
Design And Development ◽  
Waveguide Components ◽  
K Band

A Differential UWB Quasi-Yagi Antenna with A Reconfigurable Notched Band

Frequenz ◽  
2018 ◽  
Vol 72 (9-10) ◽  
pp. 401-406 ◽  
Author(s):  
Feng Wei ◽  
Xin Tong Zou ◽  
Xin Yi Wang ◽  
Bin Li ◽  
Xi Bei Zhao
Keyword(s):  
Microstrip Line ◽  
Design Procedure ◽  
Wide Band ◽  
Impedance Bandwidth ◽  
Differential Mode ◽  
Transition Structure ◽  
Notched Band ◽  
Quarter Wavelength ◽  
Yagi Antenna ◽  
Good Agreement

Abstract A compact differential ultra-wide band (UWB) planar quasi-Yagi antenna is presented in this paper. The proposed antenna consists of a balanced stepped-impedance microstrip-slotline transition structure, a driver dipole and one parasitic strip. A wide differential-mode (DM) impedance bandwidth covering from 3.8 to 9.5 GHz is realized. Meanwhile, a high and wideband common-mode (CM) suppression can be achieved by employing the balanced stepped-impedance microstrip-slotline transition structure. It is noted that the DM passband is independent from the CM response, which can significantly simplify the design procedure. In addition, a reconfigurable sharp DM notched band from 5.6 to 6.7 GHz is generated by adding one pair of quarter-wavelength varactor-loaded short-circuited stubs adjacent to the microstrip line symmetrically. In order to illustrate the effectiveness of the design, two prototypes of the antennas are designed, fabricated, and measured. A good agreement between the simulated and measured results is observed.

Thermal Design and Development of a Inverter Considering the Switch Characteristics of Wide Band Gap Powersemiconductor

2021 ◽  
Author(s):  
Seok-Gyu Han ◽  
Wan-Hee Lee ◽  
Dae-Yoen Hwang ◽  
Sang-Min Park ◽  
Jun-Hyuk Choi ◽  
...  
Keyword(s):  
Band Gap ◽  
Wide Band ◽  
Thermal Design ◽  
Design And Development ◽  
Wide Band Gap

Analytical Electromechanical Model of Cantilevered Bi-Stable Composites for Broadband Energy Harvesting

2013 ◽  
Author(s):  
Andres F. Arrieta ◽  
Tommaso Delpero ◽  
Paolo Ermanni
Keyword(s):  
Energy Harvesting ◽  
Large Amplitude ◽  
Wide Band ◽  
Electrical Energy ◽  
Ambient Vibration ◽  
Mode Shapes ◽  
Rapid Reduction ◽  
Electromechanical Model ◽  
Response Characteristics ◽  
Good Agreement

Vibration based energy harvesting has received extensive attention in the engineering community for the past decade thanks to its potential for autonomous powering small electronic devices. For this purpose, linear electromechanical devices converting mechanical to useful electrical energy have been extensively investigated. Such systems operate optimally when excited close to or at resonance, however, for these lightly damped structures small variations in the ambient vibration frequency results in a rapid reduction of performance. The idea to use nonlinearity to obtain large amplitude response in a wider frequency range, has shown the potential for achieving so called broadband energy harvesting. An interesting type of nonlinear structures exhibiting the desired broadband response characteristics are bi-stable composites. The bi-stable nature of these composites allows for designing several ranges of wide band large amplitude oscillations, from which high power can be harvested. In this paper, an analytical electromechanical model of cantilevered piezoelectric bi-stable composites for broadband harvesting is presented. The model allows to calculate the modal characteristics, such as natural frequencies and mode shapes, providing a tool for the design of bi-stable composites as harvesting devices. The generalised coupling coefficient is used to select the positioning of piezoelectric elements on the composites for maximising the conversion energy. The modal response of a test specimen is obtained and compared to theoretical results showing good agreement, thus validating the model.

Ultra-wideband elliptical patch antenna for microwave imaging of wood

2019 ◽  
Vol 11 (9) ◽  
pp. 948-966 ◽  
Author(s):  
Tale Saeidi ◽  
Idris Ismail ◽  
Wong Peng Wen ◽  
Adam R. H. Alhawari
Keyword(s):  
Low Frequency ◽  
Wide Band ◽  
Microwave Imaging ◽  
Ultra Wideband ◽  
Uniform Illumination ◽  
Elliptical Shape ◽  
Measurement Results ◽  
Simulation Results ◽  
Strip Loading ◽  
Good Agreement

AbstractThis paper presents the design of an elliptical shape ultra-wide band antenna for imaging of wood. The antenna is constructed comprising an elliptical shape of patch loaded by a stub to resonate at lower bands, strip loading at the back, and chamfered ground. Despite having miniaturized dimensions of 20 mm × 20 mm, the proposed antenna shows better results compared to recent studies. The simulation results depict a good ultra-wide bandwidth from 2.68 to 16 GHz, and 18.2–20 GHz. Besides, the proposed antenna has two low-frequency bands at 0.89–0.92 and 1.52–1.62 GHz, maximum gain of 5.48 dB, and maximum directivity of 6.9 dBi. The measurement outcomes are performed in air, plywood, and high-density wood and show a good agreement with the simulated results done using electromagnetic simulator CST. In addition to that, the measurement results of S-parameters, transmitted and received signals show a good agreement with the simulated results. Besides, the measured results illustrate a good isolation and uniform illumination among arrays as well as the received signals' shapes do not change in different environments, but only the amplitude. Hence, the proposed antenna seems to be adequate for microwave imaging of wood.

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