Open dielectric waveguides are structures used to guide electromagnetic energy in integrated circuits above the cutoff or as leaky wave antennas propagating the energy transversely out of the waveguide in a narrow region below the cutoff. In this study, the related operating regions for the hybrid EH modes of a cylindrical dielectric rod were obtained analytically. Analyses of the leaky wave characteristics of the hybrid EH modes for various radii of the rod and various dielectric constant values were performed. The guided modes existing above the cutoff with a pure real propagation constant, and the leaky wave modes existing below the cutoff with a complex propagation constant, were obtained from the coefficient matrix of the characteristic equations system of the structure using the bisection method and Davidenko’s method, respectively. Additionally, the guided modes of the structure were obtained and designated in the light of previous studies in the literature. The results show that the frequency spectrum of the antenna mode region increases as the value of the dielectric constant and the radius of the dielectric rod decrease. In addition, a circular dielectric with a smaller radius and dielectric constant had a larger frequency spectrum in the leaky wave antenna applications.

An open dielectric waveguide includes both guided propagating modes within the waveguide and radiating and evanescent modes that propagate transversely outside the waveguide. In this study, the leaky-wave characteristics of a cylindrical dielectric rod are investigated using the coefficient matrix of the system of characteristic equations and Davidenko’s method. Using the coefficient matrix of the system of characteristic equations simplified the derivative(s) required to use Davidenko’s method. The results obtained for a 10-mm radius structure with a relative dielectric constant of 4 showed that a second antenna mode region existed for higher-order hybrid HE modes and lower-order transverse magnetic (TM) modes. However, it did not exist for transverse electric (TE) modes. Additionally, the hybrid HE modes had larger leaky-wave spectrum and antenna mode regions than both the TE and TM modes. This demonstrates that for antenna applications, hybrid HE modes supply a wider frequency spectrum.

Bu çalışmada, meteorolojik verilerin takibi, güneş ve rüzgar enerjisi açısından bölge potansiyelinin gerçek veriler ile saptanması, hava veya alternatif enerji sistemleri tahmin algoritmalarında kullanılmak üzere meteorolojik verilerin toplanması amaçlarıyla Kocaeli Üniversitesi Uzunçiftlik Nuh Çimento Meslek Yüksekokulu çatısına kurulan hava istasyonu ele alınmıştır. Kurulan hava istasyonu ile bölgenin global ışıma, rüzgar hızı, rüzgar yönü, sıcaklık ve nem verileri 32 bit Arduino Due mikrodenetleyici ile toplanarak SD hafıza modülüne kayıt edilmiştir. Ayrıca veriler ESP8266 WiFi modülü aracılığıyla ThingSpeak bulut ortamına alınarak sistem bir nesnelerin interneti uygulamasına dönüştürülmüştür. Çalışma içerisinde ek olarak Ağustos 2018-Aralık 2018 döneminde sistemden elde edilen veriler kullanılarak günlük metrekare başına toplam ışıma, günlük ortalama, maksimum, minimum sıcaklık ve nem, günlük ortalama ve maksimum rüzgar hızı verileri grafikler yardımıyla sunulmuştur.

In this study, the dispersion curves of the plasma modes, which exist in gyroresonance region, have been obtained by using Method of Moment (MoM) for the plasma column loaded cylindrical waveguide. In the study, the first three modes, which have lowest degree, have been investigated. The validation of the method has been tested by comparing the exact solution of the structure which exists in the literature. Comparative results have been presented numerically and graphically. Besides absolute error curves have been given for each structure.

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