Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 59 for “"anechoic chamber"”.
-
Anechoic chamber design and acoustical analysis of room 1-051
Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1987.
-
Design of anechoic chamber instrumentation and data acquisition module for testing and analysis of the CTHA
… against electromagnetic radiation, called anechoic chambers. The objective of this work is to design and build an automated data acquisition system to map the field of physically small antennas such as a Contrawound Toroidal Helical Antenna (CTHA), placed inside an anechoic chamber built …
-
Design and Verification of a LabVIEW Automated Antenna Radiation Pattern Measurement System
… Toyon Research Corporation donated a 6’x6’x8’ anechoic chamber to the Cal Poly EE department to advance student education in the areas of antennas and wireless communications. An anechoic chamber is a room designed to suppress electromagnetic radiation reflections so that accurate measurement …
-
Structure-Property Evaluation of the Dielectric Properties of Radar Absorbing Materials in Free Space
… dielectric properties. The use of Free Space and anechoic chamber instrumentation are two such ways to achieve information on samples that are lossy, i.e. materials that have the ability to quickly dissipate EM radiation. For this work, several commercial polymer matrices were used with 4 …
-
A measurement study of 802.11n links on commodity hardware
… at diff erent times of day, and in an anechoic chamber. We find that 802.11n, which uses MIMO, presents a peculiar nature of performance in indoor and anechoic chamber environments and presents some interesting challenges as well as opportunities for better rate control algorithm design.
-
A Calibration Method for a Controlled Reception Pattern Antenna and Software Defined Radio Configuration
… CRPA and SDR system was characterized in an anechoic chamber environment to closely replicate the fielded antenna/receiver system. This combined CRPA and SDR system calibration method configuration can provide multi-antenna element characterization and calibration measurements that can be …
-
Retrieval of Free Space Radiation Patterns through Measured Data in a Non-Anechoic Environment
… measurements are usually carried out in an anechoic chamber. However, a good anechoic chamber is very expensive to construct. Previous research has attempted to compensate for the effects of extraneous fields measured in a non-anechoic environment to obtain a free space pattern that would be …
-
Prediction of sound pressure and intensity fields in rooms and near surfaces by ray tracing
… or more surfaces made of these materials, in an anechoic chamber, a scale-model room, and a full-scale office space. Prediction accuracy in the anechoic chamber, and in the presence of a single reflecting surface, greatly improved with the inclusion of phase. Further comparison with full-scale …
-
Development and Comparison of Highly Directional Loudspeakers
… Prototypes have been built and tested in an anechoic chamber. Results from computer modeling and experimental measurements will be presented and compared in this thesis.
-
A Study and Modelling of the Propagation Effects of Vegetation on Radio Waves at Centimetre-Wavelength Frequencies
… further study has been conducted in an anechoic chamber, the purpose being to investigate the depolarising effect of vegetation, to characterise and to ascertain how and to what extent the polarisation of the incident signal is changed as it passes through the vegetation without the …
-
Computer modeling of captive-carry missile simulator experiments
… two basic configurations: the closed loop in an anechoic chamber and the open loop captive carry on board a P-3 aircraft. The objective of this thesis was to develop a comprehensive Simulink model representing the two HIL missile simulator configurations. These models were then used to study the …
-
Electromagnetic effects on soybeans
… All the experiments were conducted in an anechoic chamber at a power level of 126 Watts, Frequency 100 MHz and exposure time 10 minutes. For future work, we suggest similar experiments with other frequencies and different exposure times and power levels and other varieties of soybean seeds.
-
Testing and characterization of second-order differential microphones
… research groups that do not have access to an anechoic chamber because the plane wave response is a standard by which acoustic devices are measured. This process was validated by comparing the true plane wave response of an industry standard differential microphone with its simulated plane wave …
-
Manipulation of antenna-mode radar cross-section in patch antennas
… and the actual change in RCS was measured in an anechoic chamber. The simulation data is compared to the measured data. It is seen that a predictable change in RCS occurs as load points are moved around a constant VSWR circle.
-
The Effects of Atomic Oxygen on Patch Antenna Performance and Lifetime
… frequencies than omnidirectional antennas. An AO chamber in the California Polytechnic State University San Luis Obispo’s (Cal Poly) Spacecraft Environments Testing Lab was used to expose the patch antennas for 24-hour and 48-hour tests. The 24-hour exposure saw an average AO fluence of 8.757 ± …
-
Theory, Simulation, Fabrication and Testing of Double Negative and Epsilon Near Zero Metamaterials for Microwave Applications
… a prism design and test plan geared for anechoic chamber testing and refraction measurement is proposed and built. Simulated inclusions are fabricated on FR-4 epoxy laminate boards, combined to form metamaterial structures, and tested in the Cal Poly Anechoic chamber. Results show that …
-
Multifilar Hemispherical Helical Antennas
… are calculated. Measurements, taken in the anechoic chamber at the Virginia Tech antenna range, generally confirmed the simulation results. It is shown that the bifilar hemispherical helix provides a flat gain curve over the measured bandwidth (~14%) and generally elliptical polarization …
-
Measurements and modelling of reflection and transmission from smooth and rough surfaces at 62 GHz
… at 62.4 GHz have been made inside the anechoic chamber on eight different building materials, and results are expressed as functions of observation and incident angles. It has been shown that the well-known Fresnel coefficients fail to predict reflectivity and transmissivity values when …
-
Genetic algorithm design and testing of a random element 3-D 2.4 GHZ phased array transmit antenna constructed of commercial RF microchips
… Method of Moments calculations was achieved in anechoic chamber measurements conducted with the test-bed array. Both H-plane and E-plane data runs were made with several phase steered beams. In all cases the measured data agreed with that predicted from both modeling programs. Although time …
-
Handheld Antenna Assessment Based on CV Ego-motion Position and Orientation Estimation of a Mobile Device
… method that needs to be carried out in an anechoic chamber is very inconvenient for performing frequent calibration, this method also lacks the flexibility to emulate the daily usage scenarios accurately. A potentially better solution is to devise a method to compute the dynamics of the …
Page 1 of 3