Search Results (1 - 25 of 91 Results)

Sort By  
Sort Dir
 
Results per page  

Elghannai, Ezdeen AhmedNOVEL METHOD TO CONTROL ANTENNA CURRENTS BASED ON THEORY OF CHARACTERISTIC MODES
Doctor of Philosophy, The Ohio State University, 2016, Electrical and Computer Engineering
Characteristic Mode Theory is one of the very few numerical methods that provide a great deal of physical insight because it allows us to determine the natural modes of the radiating structure. The key feature of these modes is that the total induced antenna current, input impedance/admittance and radiation pattern can be expressed as a linear weighted combination of individual modes. Using this decomposition method, it is possible to study the behavior of the individual modes, understand them and therefore control the antennas behavior; in other words, control the currents induced on the antenna structure. This dissertation advances the topic of antenna design by carefully controlling the antenna currents over the desired frequency band to achieve the desired performance specifications for a set of constraints. Here, a systematic method based on the Theory of Characteristic Modes (CM) and lumped reactive loading to achieve the goal of current control is developed. The lumped reactive loads are determined based on the desired behavior of the antenna currents. This technique can also be used to impedance match the antenna to the source/generator connected to it. The technique is much more general than the traditional impedance matching. Generally, the reactive loads that properly control the currents exhibit a combination of Foster and non-Foster behavior. The former can be implemented with lumped passive reactive components, while the latter can be implemented with lumped non-Foster circuits (NFC). The concept of current control is applied to design antennas with a wide band (impedance/pattern) behavior using reactive loads. We successfully applied this novel technique to design multi band and wide band antennas for wireless applications. The technique was developed to match the antenna to resistive and/or complex source impedance and control the radiation pattern at these frequency bands, considering size and volume constraints. A wide band patch antenna was achieved using the developed technique. In addition, the technique was applied to multi band wire less Universal Serial Bus (USB) dongle antenna that serves for WLAN IEEE 802.11 a/b/g/n band applications and Radio Frequency Identification (RFID) tag antenna for 915MHz band applications with superior performance compared to previous published results. This dissertation also discusses the total Q of an antenna from the CM standpoint. A new expression as well as additional physical information about each mode's individual contribution to the total antenna Q are provided. Finally, the theory is used to an analyze the antenna in both radiation and/or scattering modes. In the antenna scattering mode, the field scattered by an antenna contains a component that is the short circuit scattered field, and a second component that is proportional to the radiation field. In this dissertation, an analytical study of this phenomena from the CM standpoint is performed aiming to shed some light on antenna scattering phenomenon where additional physical insight is obtained and thus used to reach desire results.

Committee:

Roberto Rojas, Prof (Advisor); Fernando Teixeira, Prof (Committee Member); Robert Burkholder, Prof (Committee Member)

Subjects:

Electrical Engineering; Electromagnetics; Engineering

Keywords:

Antennas; Loaded antennas; Characteristic modes theory; Electrically small antennas; wide band antennas; reactive loading; Antenna scattering; Characteristic modes; Radar cross section; Antenna Scattering; Quality factor of Antennas

Moon, HaksuDevelopment of Very Low-Profile Ultra-Wideband VHF Antennas
Master of Science, The Ohio State University, 2011, Electrical and Computer Engineering

With the rapid growth of wireless communications and associated demand for high data-rates, many future antennas must be ultra-wideband (UWB). A single antenna is certainly a most attractive solution to handling the large bandwidth requirements. Designing such an antenna that is concurrently of low-profile is necessary for mounting on a variety of grounds and airborne vehicles. This thesis presents a new low-profile UWB antenna concept. The concept is based on a shorted low-profile patch strategically fed on the open side to obtain wide bandwidth. For miniaturizing the proposed antenna and widening its bandwidth, it was loaded with ferrite bars placed between the patch plate and the ground plane. Much of the design effort for this antenna is focused on the location and shape of the ferrite bars. Minimization of antenna weight is also performed. The developed ferrite-loaded shorted-patch concept is compared with a low-profile monopole to demonstrate its superior bandwidth and gain performance over the frequency range from 30 MHz to 400 MHz. Prototype versions of various ferrite-loaded shorted-patch antennas were fabricated and measured for validation. A version of these was the design that has a planar patch as small as λ/16 in diameter and a height of only λ/200 at the lowest operational frequency.

We note that the ferrite loading design led to 5 to 14 dB gain improvement in the low frequency range below 50 MHz. The resulting gain was actually close to the optimal Fano-Bode limit. An important aspect of the ferrite loading design was the use of commercially available materials. Although these were lossy at high frequencies, their strategic placement resulted in minimal gain reduction.

Committee:

John Volakis, Prof. (Advisor); Chi-Chih Chen, Dr. (Advisor)

Subjects:

Electrical Engineering; Electromagnetics; Electromagnetism

Keywords:

low-profile antennas; small antennas; ultra-wideband antennas; ferrite loading

Mumcu, GokhanEM Characterization of Magnetic Photonic / Degenerate Band Edge Crystals and Related Antenna Realizations
Doctor of Philosophy, The Ohio State University, 2008, Electrical and Computer Engineering

Extraordinary properties found in engineered metamaterials have drawn great interest as they can address industry demands for small, light-weight, and multifunctional devices. It is not therefore surprising that a variety of artificial materials are being widely considered for various radio frequency (RF) applications. Among these metamaterials, a recently introduced class of anisotropic photonic crystals, namely magnetic photonic (MPC) and degenerate band edge (DBE) crystals, has been shown to exhibit unique propagation modes as compared to regular periodic assemblies. For the first time, this dissertation carries out computational and experimental analysis of these new crystals for specific RF applications. Our ultimate goal is to develop high gain antenna apertures and miniature footprint antennas. In this context, this dissertation begins by establishing an understanding of the fundamental electromagnetic properties of 1D DBE and MPC crystals using the transfer matrix and spectral domain method of moments (MoM) computations. This is followed by numerical characterization of 3D DBE crystals via surface integral equations. Upon successful demonstration of the DBE mode for improved antenna performance, a measurement setup is presented to characterize low loss uniaxial materials. Subsequently, Specifically, a finite DBE assembly is built and shown to exhibit large aperture efficiency for conformal high gain antenna applications.

The second half of the dissertation introduces a novel coupled transmission line concept capable of emulating DBE mode on otherwise uniform microwave substrates. Using this novel dual transmission line concept, we present examples of several small antennas on low and high contrast substrates, and fabricate a prototype to experimentally verify the printed slow wave concepts. The measured DBE antenna is shown to perform better than other recently published metamaterial antennas. It is therefore very attractive for several RF applications requiring small and efficient antennas (such as RF identification (RFID) tags or mobile communications). The last chapter presents a lumped circuit DBE model and suggest improvement to existing DBE antennas by introducing lumped elements into the transmission lines.

Committee:

John Volakis, L (Advisor); Jin-Fa Lee (Committee Member); Roberto Rojas, G (Committee Member); Kubilay Sertel (Committee Member)

Subjects:

Electrical Engineering; Electromagnetism

Keywords:

magnetic photonic crystals; MPC; degenerate band edge crystals; DBE; anisotropic media; metamaterials; printed antennas; miniature antennas; equivalent circuit model; surface integral equation; SIE; uniaxial medium; dyadic Green's function

Apaydin, NilNovel Implementations of Coupled Microstrip Lines on Magnetic Substrates
Doctor of Philosophy, The Ohio State University, 2013, Electrical and Computer Engineering

The demand for small, light-weight and multi-functional wireless devices continues to increase, fueled by growth in the commercial and defense industry. Although the RF back-ends allowed for multi-functionality and miniaturization via improvements in semiconductors, the RF front-ends using conventional materials have not evolved analogously. As such, use of novel and periodic materials has become a new frontier for smaller and multi-functional integrated RF devices.

This dissertation presents how to realize unprecedented propagation and radiation properties using periodic anisotropic material arrangements. This was done by manipulating the well-known K-ω diagrams. Our previous designs with engineered anisotropy were shown to lead to high sensitivity and non-reciprocal RF devices. Motivated by these novel properties, in this dissertation, we realize similar propagation behavior using printed layouts and present two different applications. Such printed layouts are attractive for low-cost antennas and were already shown to lead to miniaturization and improved gain-bandwidth performance.

The first design is based on coupled transmission lines (TLs) on a ferrite substrate for guided-wave applications, where strong nonreciprocity is attained in the guided/slow wave region (with |β|>k0, β is the phase constant in the substrate, and k0 is the free space wavenumber) of the K-ω diagram. Previous work has theoretically demonstrated that nonreciprocal slow group velocity (frozen) mode can be supported on this design. To observe its existence experimentally, we constructed 2 printed prototypes and employ "T-matrix method" to determine the dispersion properties by measuring the S-parameters of these finite periodic prototypes. Through careful measurements, the frozen mode was observed to propagate at a significantly slower speed (286 times slower) than the speed of light.

The second design utilizes the same coupled-line geometry to realize nonreciprocal radiation through leaky/fast waves. This was done by tuning the first fast space harmonic (|β-1|≤k0) of the dominant mode to be fast and to exhibit spectral asymmetry at the operation frequency. For proper operation, ferrite needs be biased with an external bias field. However, the nonuniformities in the bias field alter the leaky wave antenna's (LWA) radiation properties and limit its scanning performance.

To reduce the bias field nonuniformities, a new miniaturized LWA is proposed for wide angle scanning via magnetic tuning. This new design is comprised of coupled composite right left handed (CRLH) TLs, which incorporate series capacitors and shunt inductors and lead to significantly miniaturized LWAs. As the bias field nonuniformity is less over the smaller footprint, we were able to scan the beam in the E-plane by 80° by tuning the bias field (i.e. changing the distance between the permanent magnet and the LWA). Clearly, this approach is not practical. As a future direction, a new class of magnetoelectric (ME)-based LWA is proposed for electrical beam-steering. In this design, the LWA is considered on a ME composite film, comprised of ferrite and piezoelectric layers. The voltage VDC applied to the piezo layer changes the magnetic field inside the ferrite layer due to the magnetostrictive strain at the interface. This tunes the permeability of the ferrite to achieve beam-steering.

Committee:

John L. Volakis (Advisor); Kubilay Sertel (Advisor); Fernando L. Teixeira (Committee Member); Mizejewski Linda (Committee Member)

Subjects:

Electrical Engineering; Electromagnetism

Keywords:

leaky-wave antennas, ferrite, magnetic materials, anisotropy, beamsteering, magnetic beamsteering, nonreciprocity

Pistorius, C. W. I.New main reflector, subreflector and dual chamber concepts for compact range applications /
Doctor of Philosophy, The Ohio State University, 1986, Graduate School

Committee:

Not Provided (Other)

Subjects:

Engineering

Keywords:

Antennas

Chang, Yueh-ChiAnalysis of reflector antennas with array feeds using multi-point GTD and extended aperture integration/
Doctor of Philosophy, The Ohio State University, 1984, Graduate School

Committee:

Not Provided (Other)

Subjects:

Engineering

Keywords:

Antennas;Antenna arrays;Diffraction

Kim, Jacob Jeong-GeunSimulation and analysis of airborne antenna radiation patterns /
Doctor of Philosophy, The Ohio State University, 1985, Graduate School

Committee:

Not Provided (Other)

Subjects:

Engineering

Keywords:

Antennas ;Airplanes--Fuselage

Greer, Eric DaleHigh frequency scattering from multiple finite elliptic cylinders /
Doctor of Philosophy, The Ohio State University, 1981, Graduate School

Committee:

Not Provided (Other)

Subjects:

Engineering

Keywords:

Scattering;Antennas

Fenn, Alan JeffreyMoment method calculation of reflection coefficient for waveguide elements in a finite planar phased antenna array /
Doctor of Philosophy, The Ohio State University, 1978, Graduate School

Committee:

Not Provided (Other)

Subjects:

Engineering

Keywords:

Phased array antennas

Kornbau, Thomas WayneAnalysis of periodic arrays of rotated linear dipoles, rotated crossed dipoles, and of biplanar dipole arrays in dielectric /
Doctor of Philosophy, The Ohio State University, 1984, Graduate School

Committee:

Not Provided (Other)

Subjects:

Engineering

Keywords:

Antennas;Dielectrics

Tourdot, James EugeneA sequential, self-synchronous, beam tagging technique for adaptive control of transmitting arrays /
Doctor of Philosophy, The Ohio State University, 1968, Graduate School

Committee:

Not Provided (Other)

Subjects:

Engineering

Keywords:

Antennas

Chen, Chin-Long JamesThe near field analysis of aperture and spiral antennas by the plane wave spectrum method /
Doctor of Philosophy, The Ohio State University, 1974, Graduate School

Committee:

Not Provided (Other)

Subjects:

Engineering

Keywords:

Antennas

Newman, Edward H.Analysis of strip antennas in the presence of a dielectric inhomogeneity /
Doctor of Philosophy, The Ohio State University, 1974, Graduate School

Committee:

Not Provided (Other)

Subjects:

Engineering

Keywords:

Antennas ;Dielectrics

Lawrie, Richard EdwardOptimization of the directivity of a planar, equiangular, spiral antenna /
Doctor of Philosophy, The Ohio State University, 1968, Graduate School

Committee:

Not Provided (Other)

Subjects:

Engineering

Keywords:

Antennas

Song, Keum SuNon-Foster Impedance Matching and Loading Networks for Electrically Small Antennas
Doctor of Philosophy, The Ohio State University, 2011, Electrical and Computer Engineering

The demand for wide-band small antennas is steadily increasing for both civilian and military applications due to the explosive growth of wireless communications systems. Linearly polarized electrically small antennas can be generally classified as TM10 and TE10 mode antennas. For a TM10 mode antenna, the input impedance of the antenna is considerably reactive with a small real part. In contrast, the input admittance of a TE10 mode antenna is characterized by a high susceptance and a small conductance, i.e. the input impedance is almost a short. It is therefore critical to match the antenna to a receiver (or transmitter) to optimize the transfer of power in the frequency range of interest. With conventional passive matching networks, the antennas can be only matched over narrow frequency bands. However, Non-Foster matching networks composed of negative capacitors and/or inductors can in principle match the antenna over wide frequency bands because Non-Foster matching networks can overcome the gain-bandwidth restrictions derived by Bode-Fano. In this dissertation, the design, implementation, and measurement of two Non-Foster matching networks for a TM10 mode antenna and a Non-Foster loading network for a TE10 mode antenna are the topics to be discussed, which improve performance of both types of electrically small antennas over broad frequency ranges. These devices take advantage of the unique property of Non-Foster impedances, counter-clock wise rotation on the Smith chart as the frequency increases. First, a systematic methodology is introduced to design a Non-Foster matching network for an electrically small antenna. Key steps in the proposed methodology are presented to demonstrate how to realize a fabricated Non-Foster capacitor for a 3′′ electrically small monopole receiver antenna. Based on experimental results, it is verified that Non-Foster matching networks will improve both the antenna gain and the signal to noise ratio. Second, a Non-Foster matching network with a series connection of negative capacitor-inductor for the same 3′′ small monopole antenna is fabricated and tested. This Non-Foster matching network improves the performance of the antenna to higher frequencies. Through measured and simulated data, it is shown that the antenna with a negative capacitor-inductor has an advantage over both the antenna with and without a negative capacitor. To the best of our knowledge, it is the first time that a series combination of a negative capacitor-inductor has been demonstrated with measured data when connected to an actual antenna.

Lastly, this dissertation discusses a method to improve the performance of a small loop antenna by using a Non-Foster inductor loading. The Non-Foster loading network (located away from the input port of the antenna) is employed to improve the impedance mismatch and also maintain an omni-directional antenna pattern at higher frequencies than the case of a loop antenna with a Non-Foster matching network and a short loading (stands for a small loop antenna). Although the experimental radiation patterns are somewhat different from the simulated data, it is found that the measured antenna gain and SNR with the Non-Foster inductor loading are improved when compared to case with a short loading. To the best of our knowledge, it is the first time that a fabricated Non-Foster impedance loading network was applied to an actual antenna.

Committee:

Roberto Rojas, Ph.D. (Advisor); Fernando Teixeira, Ph.D. (Committee Member); Patrick Roblin, Ph.D. (Committee Member)

Subjects:

Electrical Engineering

Keywords:

Non-Foster impedance; Non-Foster matching network; Non-Foster loading network; Electrically small antennas; Negative Capacitor; Negative Inductor

Zeineddin, Rafik PaulNumerical electromagnetics codes: Problems, solutions and applications
Master of Science (MS), Ohio University, 1993, Electrical Engineering & Computer Science (Engineering and Technology)

Numerical electromagnetics codes: Problems, solutions and applications

Committee:

Roger Radcliff (Advisor)

Keywords:

numerical electromagnetics codes; antennas; MININEC; Theoretical Modeling; Method of Moments

Obeidat, Khaled AhmadDesign Methodology for Wideband Electrically Small Antennas (ESA) Based on the Theory of Characteristic Modes (CM)
Doctor of Philosophy, The Ohio State University, 2010, Electrical and Computer Engineering
Emerging broadband applications with market pressures for miniaturized communication devices have encouraged the use of electrically small antennas (ESA) and highly integrated RF circuitry for high volume low cost mobile devices. This research work focuses on developing a novel scheme to design wideband electrical small antennas that incorporates active and passive loading as well as passive matching networks. Several antennas designed using the proposed design technique and built and measured to assess their performance and to validate the design methodology. Previously, the theory of Characteristic Modes (CM) has been used mostly for antennas analysis. However; in this chapter a design procedure is proposed for designing wide band (both the input impedance bandwidth and the far field pattern bandwidth) electrically small to mid size antennas using the CM in conjunction with the theory of matching networks developed by Carlin. In order to increase the antenna gain, the antenna input impedance mismatch loss needs to be minimized by carefully exciting the antenna either at one port or at multiple ports and/or load the antenna at different ports along the antenna body such that the Q factor in the desired frequency range is suitable for wideband matching network design. The excitation (feeding structure), the loading of the antenna and/or even small modifications to the antenna structure can be modeled and understood by studying the eigenvalues and their corresponding eigencurrents obtained from the CM of the antenna structure. A brief discussion of the theory of Characteristic Modes (CM) will be presented and reviewed before the proposed design scheme is introduced. The design method will be used to demonstrate CM applications to widen the frequency bandwidth of the input impedance of an electrically small Vee shape Antenna and to obtain vertically polarized Omni-directional patterns for such antenna over a wide bandwidth. A loading technique based on the CM to either design frequency reconfigurable antennas or broaden their bandwidth by Non-Foster loading will also be discussed as part of the design methodology. In the Appendix, a brief discussion of the fundamental limits of electrical small antennas is presented and then followed by a discussion of the fundamental limits of the impedance bandwidth of the ESA when a passive matching network is used. Matching network implemented using Non-Foster matching is also discussed in the appendix.

Committee:

Roberto G. Rojas, PhD (Advisor); Garbacz Robert, PhD (Committee Member); Teixeira Fernando, PhD (Committee Member)

Subjects:

Electrical Engineering; Engineering; Experiments

Keywords:

Theory of Characteristic Modes; electrically small antennas ; Matching Network ; Parallel Resonance ; reconfigurable antenna; wideband antenna ; conformal antenna ; non-foster loads; NIC; Cavity modes; Patch antenna; loop antenna; PIFA

Doane, Jonathan PWideband Low-Profile Antenna Arrays: Fundamental Limits and Practical Implementations
Doctor of Philosophy, The Ohio State University, 2013, Electrical and Computer Engineering
Advanced wireless communication and sensing systems have created a growing need for high performance, compact antennas. Low-profile wideband phased arrays are of particular interest, and have recently been shown to be capable of extremely large bandwidths. However, the size, weight, and cost of phased arrays still makes them impractical for many applications. The development of thinner, lightweight, and inexpensive wideband arrays is critical to improving the capabilities of small platforms such as small unmanned aerial vehicles. Like all antennas, phased arrays are limited by a fundamental compromise between size and performance. Although the theoretical limitations of electrically small antennas have been well known for over 60 years, similarly general limits have not yet been developed for periodic antenna arrays. In the first part of this thesis, we derive a new fundamental bandwidth limit for any periodic array that is backed by a conducting ground plane and constructed from passive and reciprocal materials. This limit is related to several critical design factors, including the array's thickness, polarization, scan angle, materials used, as well as the overall complexity of the array design. We also consider the common case when all radiating currents are confined to a thin planar sheet placed above the ground plane. We show here that such planar phased arrays have a fundamental impedance bandwidth limit of 8.3:1 (with VSWR ≤ 2:1), in the absence of material loading. This bandwidth may be further improved by adding dielectric superstrate or magnetic substrate material layers. Knowledge of such fundamental bandwidth limits is extremely useful in the design of practical wideband arrays, which is the focus of the second part of this thesis. A key challenge with many wideband arrays is developing a feed circuit that supports extremely wide bandwidths without significantly adding to the size, weight, and cost of the design. Here, we demonstrate a novel approach that overcomes this problem by exploiting the natural reactance of the feed circuit as a simple impedance matching network for the array. The result is a simultaneous reduction in size and weight and improvement in bandwidth compared to other feeding techniques. We refer to our design as the Tightly Coupled Dipole Array with Integrated Balun (TCDA-IB), and it achieves 7.35:1 bandwidth while maintaining a low VSWR of ≤ 2.65:1 while scanning to ± 45° in all planes. A prototype 8×8 array was constructed and demonstrated excellent performance relative to simulation. We also demonstrate that by adding reconfigurable components to the TCDA-IB, its maximum scan angle may by increased to as much as ± 70° while maintaining a 5:1 impedance bandwidth. Our fundamental bandwidth limits reveal for the first time the extent of the realizable design space for wideband low-profile arrays, and suggest there are significant opportunities for further improvement. Several practical techniques are also presented for increasing bandwidth and scanning performance while reducing the total size, weight and cost of the array. In summary, the ongoing development of high-performance wideband low-profile arrays will likely remain an important and fertile area of research for the foreseeable future.

Committee:

John Volakis, Dr (Advisor); Kubilay Sertel, Dr (Advisor); Chris Baker, Dr (Committee Member)

Subjects:

Electrical Engineering; Electromagnetics; Physics

Keywords:

Antennas; Antenna Arrays; Wideband Arrays; Bandwidth Limits; Tightly Coupled Arrays

Hall, John J.The design, construction and control of a four-degree-of-freedom hybrid parallel/serial motion platform for the calibration of multi-axis inertial measurement units
Master of Science (MS), Ohio University, 2000, Mechanical Engineering (Engineering)

The Department of Mechanical Engineering and the Avionics Engineering Center at Ohio University are developing an electromechanical system for the calibration of an inertial measurement unit (IMU) using global positioning system (GPS) antennas. The GPS antennas and IMU are mounted to a common platform to be oriented in the angular roll, pitch, and yaw motions. Vertical motion is also included to test the systems in a vibrational manner. A four-DOF system based n the parallel Carpal Wrist has been developed as a test platform for this calibration process. High-accuracy positioning is not required from the platform since the GPS technology provides absolute positioning data for the IMU calibration.

Committee:

Robert Williams II (Advisor)

Subjects:

Engineering, Mechanical

Keywords:

hybrid motion platform; parallel/serial motion platform; calibration of multi-axis; inertial measurement units; IMU; global positioning system; GPS antennas

Vural, SerdarInformation propagation in wireless sensor networks using directional antennas
Doctor of Philosophy, The Ohio State University, 2007, Electrical Engineering
The information propagation capability of Wireless Sensor Networks (WSN) is directly related with the properties of multihop paths. Two main measures of the multihop data propagation capability are the maximum Euclidean distance that can be covered in a multihop path and the effectiveness of the medium access control (MAC) protocol. To achieve high propagation capacity, MAC protocols should enhance the channel use by maximizing simultaneous traffics and reducing end-to-end delay in high data load scenarios often encountered in WSN data collection applications. In this regards, directional antennas offer various benefits such as the extended communication ranges, spatial reuse capability, and reduced interference patterns that enable higher network performance compared to omnidirectional antennas. In this thesis, the maximum multihop Euclidean distance covered by directional packet transmissions is evaluated for both linear and planar WSNs using analytical modeling of distance distributions. Expressions for calculating the distribution parameters are derived and provided. Comparison of experimental and analytical results demonstrate the high accuracy of the proposed models in estimating distance distributions. Furthermore, a WSN security application which utilizes the derived models for verifying sensor locations is presented. The second contribution of this thesis is the Smart Antenna-Based MAC (SAMAC) protocol designed for multihop data collection applications for WSNs with sectored antennas. A detailed protocol description as well as performance evaluation results are provided. Simulation results demonstrate that SAMAC with sectored antennas improves end-to-end delay, data throughput, and data delivery ratio under high data generation rates and highly loaded traffic conditions compared to IEEE 802.11 with omnidirectional antennas.

Committee:

Eylem Ekici (Advisor)

Keywords:

wireless sensor networks; directional antennas; information propagation

Ekelman, Ernest PaulA hybrid technique for combining the moment method treatment of wire antennas with the GTD for curved surfaces /
Doctor of Philosophy, The Ohio State University, 1978, Graduate School

Committee:

Not Provided (Other)

Subjects:

Engineering

Keywords:

Antennas

Kent, Brian MichaelImpedance properties of an infinite array of non-planar rectangular loop antennas embedded in a general stratified medium /
Doctor of Philosophy, The Ohio State University, 1984, Graduate School

Committee:

Not Provided (Other)

Subjects:

Engineering

Keywords:

Phased array antennas

Lambert, Kevin M.An environmental model for calculating the antenna temperature of earth based microwave antennas /
Doctor of Philosophy, The Ohio State University, 1987, Graduate School

Committee:

Not Provided (Other)

Subjects:

Engineering

Keywords:

Earth temperature;Microwave antennas

Yoon, Hwan-Sik.Design, modeling, and optimization of a mechanically reconfigurable smart reflector antenna system /
Doctor of Philosophy, The Ohio State University, 2002, Graduate School

Committee:

Not Provided (Other)

Subjects:

Engineering

Keywords:

Antennas

Schwab, Leonard MartinVHF communications repeaters using crossed dipole antennas /
Doctor of Philosophy, The Ohio State University, 1971, Graduate School

Committee:

Not Provided (Other)

Subjects:

Engineering

Keywords:

Antennas

Next Page