Dusan Nesic

Printed Planar 8

A new type of printed millimeter planar antenna with circular polarization for 60-GHz range is proposed. Radiation elements with two open tape rings are arranged in a two-dimensional 8×8 antenna array. Feeding is synphase network with tapered symmetrical (balanced) microstrip in the same plane as the radiation elements. The 8×8 array is fabricated in the conventional technology. To test reproducibility, three samples are fabricated. Measured S11 (VSWR), gain, and axial ratio (AR) are very good and in very good agreement between all three samples: AR<;3 dB about 25% and gain near 20 dBi.

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Different types of printed antennas for millimeter ranges such as high gain (narrow beam) with linear and circular polarization, sector antennas with azimuth angle of 60/spl deg/, 90/spl deg/ and 180/spl deg/, and omnidirectional antennas are proposed. All types are suitable for integration with active microwave and millimeter wave amplifiers, and down and upconvectors. Also, the proposed sector and omnidirectional antennas are practically applicable for the lower microwave range of 5 GHz that is included in the new generation of communication systems for 60 GHz range.

8 Array Antenna With Circular Polarization for Millimeter-Wave Application

A wireless system for liquid level measurement is presented. It is developed in order to meet stringent power consumption requirements, but without sacrificing the accuracy of the built-in pressure sensor. The communication is realized using Bluetooth modules. An alternative solution based on radio units for 10.4 GHz is also discussed. The receiver is a personal computer with both the radio module and the appropriate software for reception and presentation of the acquired data. The developed wireless sensors have a very high performance/power consumption ratio.

Antenna solution for future communication devices in mm-wave range

In this paper new types of (1-D) microstrip photonic band-gap (PBG) filters are presented. They have sinusoidal variation of the characteristic impedance in function of the length along the microstrip line. They are, also, without etching in the ground plane. Band-stop, band-pass and low-pass filters are simulated, realized and measured. Band-stop filters give only one band-gap (without harmonic response). Band-pass and low-pass filters are serial connections of two or three band-stop filters and give very good characteristics. Agreement between simulation and measurement is very good.

A Wireless System for Liquid Level Measurement

Concept of design and realization of high gain printed antenna structures is presented. They consist of antenna array, subreflector, feeding network and bal-un, all printed on the same dielectric substrate. Linear array is positioned on the axis focus of the cylindrical parabolic reflector. Results are presented for the range around 26 GHz with side lobe suppression (SLS) of 30 dB as well as for the range around 60 GHz. An example of design, optimization and realization of the high gain antenna around 23 GHz with cylindrical-parabolic reflector is given in the second part of the paper. In all reported cases agreement between simulated and measured results is very good.

1-D Microstrip PBG Filters Without Etching in the Ground Plane and with Sinusoidal Variation of the Characteristic Impedance

Novel design of low-pass microwave filters based on cascading of identical unit cells is proposed. Dispersion relation is used to determine the cell parameters for a given relative stop-band width. For a filter consisting of two cells, each made of single- or two-section transmission lines, the design formulas and curves are presented. Based on them typical filters are designed, fabricated, and measured. The presented filters feature a deep stop band and a wide rejection band, which can be controlled within the proposed design procedure. The design procedure and the simulation results are verified experimentally by measurement of the fabricated structures containing two and three cells.

Printed antenna arrays with cylindrical parabolic reflector

Based on the well known theory of infinite periodic structures, analytical theory of EBG (electromagnetic band gap) cells suppressing 3 higher (spurious) stop-bands is developed. Using such cells in a cascade the straight-forward procedure for design of the corresponding EBG band-stop filter is proposed, with possibility to control the width and the depth of the stop-band. The analytical theory is confirmed by the EM simulation of a filter realized in the microstrip technology and by measurement of the fabricated model.

Low-pass filter with deep and wide stop band and controllable rejection bandwidth

In this paper we introduce new millimeter wave printed arrays with eight axially placed dipoles fed by a symphase network with the corner reflector. Three different typical beamwidths are investigated by a variation of the corner angle. Antennas are simulated and realized in the frequency range about 26 GHz which is popular for microwave communication networks. Three antennas are presented with different H-plane beamwidths (intended for azimuth) of 55/spl deg/, 110/spl deg/, and 180/spl deg/ and gains of 19.3 dBi, 16.5 dBi, and 14 dBi respectively, all having E-plane beamwidth of 7/spl deg/ (intended for elevation). Losses are less than 1 dB.

EBG band-stop filter with suppression of 3 spurious stop-bands

Within research toward a new generation of in-door communication systems, utilization of frequencies in the higher microwave and lower MM-wave bands may play an important role in future. One of the barriers to fast market introduction is convenient inherently low cost RF front ends to be realized in planar technology, moreover with integrated antennas. In this paper, a solution for an up converter with an integrated antenna at 5 GHz (non-licensed/HIPERLAN band) to 24 GHz (ISM band) is presented. The results may also trace work on the future 100 GHz systems. A solution with a sector antenna is successfully implemented and described in more detail. The measured results have verified the proposed concept.

Millimeter wave corner reflector antenna array

In this paper a new type of microwave position sensor is introduced. It is an angular microstrip sensor based on a slot etched in the ground plane. It is a microstrip stub resonator with slow-wave effect induced by the slot. Covering the slot decreases slow-wave effect and increases resonant frequency. There is a correspondence between the covered angle and the resonant frequency.