Over the Air Measurement Techniques for Time Varying Electrically Small AntennasHall, Owen Electrically small antennasESAChu-Harrington limitcapacitance modulationbandwidth enhancementefficiencytime-varying capacitanceover-the-air testingError Vector MagnitudeEVMBit Error RateBERModulation Error RatioMERsignal analysisimpedance matchingharmonic generationRF circuitsantenna performancenonlinearityresonant frequencyQ-factorwireless communicationadaptive tuningcircuit optimizationsystem losseselectromagnetic compatibilityRF measurementstesting methodologyantenna miniaturizationreal-time signal processingElectrically Small AntennasChu-Harrington LimitCapacitance ModulationBandwidthTime-varying CapacitanceOver-the-air testingImpedance MatchingRF CircuitsAntenna PerformanceTestingAntenna MiniaturizationSimulationAntenna TestingComputer EngineeringB SAntennas are fundamental to modern wireless communication, playing a critical role in applications ranging from aerospace systems to portable devices. However, electrically small antennas (ESAs) are inherently constrained by the Chu-Harrington limit, which imposes trade offs between size, bandwidth, and efficiency. This thesis investigates the potential of time varying capacitance in ESAs to enhance bandwidth and overall performance beyond these traditional limitations. Through an over-the-air testing setup, this work evaluates the impact of capacitance modulation on key performance metrics, including Error Vector Magnitude (EVM), Bit Error Rate (BER), and Modulation Error Ratio (MER). Most significantly, an original testing methodology is introduced, incorporating real-time signal analysis to quantify performance improvements over conventional ESA designs. Experimental results demonstrate that while capacitance modulation introduces measurable variations in signal fidelity, practical implementation challenges such as component non-idealities and system losses hinder clear performance gains. These findings suggest that while time-varying capacitance remains a promising approach, additional refinements in circuit design and testing conditions are necessary to fully unlock its potential. This work provides a foundation for future studies by outlining key technical barriers and proposing paths for further optimization in ESA development.Gregory Huff, Thesis SupervisorJohn Morgan Sampson, Thesis Honors Advisoropen_access2025-04-22T22:03:29Zhttps://honors.libraries.psu.edu/catalog/9567ozh5066