MSc Wireless Communication and Sensing

Graduation project (45 EC)

The thesis project is the last study unit of the programme and serves to prove that you acquired the academic competencies of a Master of Science in Telecommunications. The project involves a research or design task with sufficient academic level.

The project may be executed within a research program at TU Delft, or in a suitable research institute or company. The project must be carried out with a systematic approach and should include all phases of a research or design project: analysis, modelling, implementation/construction and validation/evaluation.

The student executes the thesis project independently, with guidance of a thesis supervisor and under the responsibility of the full professor of one of the research groups involved in the Telecommunications programme.

MSc project proposals

Some examples of thesis topics (this list is not exhaustive).
EIMagneto-mechanical micro-antenna for implantable devices
Magneto-mechanical micro-antenna for implantable devices
[2023-24] GaN Accelerometers for Space Exploration
ELCAHardware Accelerated AI for Digital Predistortion
Efficient Transformer for Keyword Spotting
MS3[New!] Sparse spiking neural networks for radar-based human activity recognition (15.11.2022)
[New! TUD-NXP] Fusion of mono-static and bi-static radar responses (01.12.2022)
[New! TUD-NXP] Codesign of 2D Antenna Array and DOA Estimation (01.12.2022)
[New!] Cognitive Radar: Semidefinite Programming Waveform Generation using Neural Networks (25.11.2022)
SPSSignal processing for wearable sensing of heart rhythm and function
Detecting anomaly patterns in networks
Data reconstruction on networks
Intelligent Reflecting Surfaces aided communication algorithms
Intelligent Reflecting Surfaces
MIMO radar for automotive applications
Signal Design for Accurate Time-of-Arrival Estimation Using Sparse Subband Signals
Digital processing for large pixel array 3D-TOF systems
Matched subspace methods for outage detection in smart grids
Analyzing the characteristics of a leader in a diffusion network
Design of Sparse Network Control
Joint Communication and Radar Sensing
Sparse Nonuniform Optical Phased Array Design
Acoustic transfer function estimation for beamforming applications
Will High-Mobility Modulations Open Up the Ocean?
Distributed processing for multiple radar nodes

Thesis examples

2012 N. ZhangWi-Fi Direct based Smart Set-up (WDSS) in Lighting Systems
H. CetinSpectrum Sharing among Cellular Operators from a Game Theoretical Cognitive and Cooperative Networking Perspective
2011 K. DongPerformance and fairness enhancement in ZigBee networks
E. P. StoutDesign and evaluation of a simulation environment for evaluating departure scheduling algorithms
D. PramudiwatiLTE System Performance in Relation to Wideband Channel Properties
E.G. Diaz CastellanosPerformance Analysis and Improvement of Topology Discovery Protocols in Home Networks
P. GuanCombining relaying and base station coordination for improving cell-edge multi-user performance in 3GPP LTE-Advanced networks
A. ZhaoReliable In-Vehicle FlexRay Network Scheduler Design
T. DikambaDownlink Scheduling in 3GPP Long Term Evolution (LTE)
S. BensdorpComparative study of light trapping strategies in thin film solar cells
2010 S. AsoodehOn Achieving the Minimum Energy for Sending One Single Bit with Feedback
K.S. WeldemichaelIntegrating TETRA with Wireless Mesh Networks
X. TianDesign and Implementation of Synchronization of WPAN Devices for Multimedia Playback
F.B. BadinradSystem Design for a High Data Rate Wireless Infrared Multi language Distribution system
A. KrishnakumarModelling the Dynamic Nature of Networks, Enabling Smart Living
2009 V.S. RaoAllocation of Opportunistic Spectrum for Cognitive Radio Ad hoc Networks
J. HaoA Multi-hop Aware Scheduling Mechanism for HSDPA and IEEE 802.11 Integrated Network
X. CuiImproving ZigBee Networks Robustness with Multi-channel Capability
H. DabbaghFree-space Emulator of 60GHz Directional Antenna Equipment
J. HeDesign and Implementation of a Wireless Sensor Network Testbed
M. HawasEvaluation of dependability of MAC and routing protocols in personal networks
M.T. NgoNew upper bounds on the separating redundancy of linear block codes
X. Zhang XinTransmission Power Adaptation Using Link Quality Estimation In IEEE802.11
S.G. GunputConnectivity Maintenance for mmWave WPANs
ES 2015 A.Y. MajidBetter Mobility Support for Radio Spectrum White Space-enabled Devices
M.G. GolinskiDesigning efficient wireless power transfer networks
A.W. DoffSensor-Assisted Movement Identification and Prediction for Beamformed 60 GHz Links
2013 F. AnDensity Adaptive Sleep Scheduling in Wireless Sensor Networks
Tarikul IslamStatistical Modeling of Intelligent Transportation Systems Communication Channels
2012 P. KalyanasundaramCooperative Spectrum Sensing Algorithms in WBAN
P.P. ElavarasuWireless LAN Optimization of HQ audio conferencing system using application layer protocol
P.G. RaghavendraraoVoice over LTE
P.S. GaonkarMap updates: a VANET application
2011 B. Wikan HantoroDistributed Beamforming for Cognitive Radio Networks
Y. LiuGreen Routing Protocols Employing Dual-Radio Cooperation
A.K. KhatibiEvent-driven MAC Protocol For Dual-Radio Cooperation
2010 Y. ZhaoAnalyzing mobility models
G.M. OlcerFuture home networks: Connectivity in 60 GHz Home Networks
2009 R. Doost MohammadyCognitive Radio Design: An SDR Approach
MS3 2022 Max Cortés PeraltaJoint human motion recognition and breathing frequency estimation for indoor healthcare applications
Giorgios TsakirakisClassification of Birds and Drones Exploiting Kinematic Properties for Surveillance Radars Using Machine Learning Techniques
Qinyu LiuDesign of the AiP feeding lines at 100GHz with low loss, high isolation and good impedance match in high definition fan-out technology
Zhongyuan GuoPoint Transformer-Based Human Activity Recognition using high-dimensional Radar Point Clouds
Bet Rufas TalamàsMultiple people detection and localization with multistatic UWB radar in multipath environments for the automotive industry
Yubin ZhaoAngle-insensitive Human Motion and Posture Recognition Based on 2D FMCW MIMO Radar and Deep Learning Classifiers
2021 Huaiyang GongDual-polarization multi-frequency radar data processing for moving target detection
Ashwath Balasubramanianmm-Wave Heatsink Antenna Array Design for Low-Sidelobe and Low-Temperature
Gopika SudhakaranModeling and simulation of future multi-user communication systems including capacity-driven array synthesis and beamforming
Yichuang HanContactless Vital Signs Monitoring via Radar Sensing for Sleep Applications
Marta Buenaventura CampsDesign of a sparse irregular array for beyond 5G base stations
Erkut YigitAutomotive Radar Self-Diagnostic Using Calibration Targets that are Embedded in Road Infrastructure
Jelle BoutDesign of a Wideband Phased Patch Antenna Array.
2020 Tworit DashComputationally Efficient Conical Horn Antenna Design
Niels de JongExploiting a multi channel receiver array in ISAR imaging: Concerning clutter suppression for maritime targets in an airborne setup
MSc Wietse BouwmeesterConformal Phased Array for DISTURB
Robin van GaalenLocalization of Autonomous Vehicle using 1D Automotive Radar Sensor
2019 Jiadi ZhangSuper-resolution Algorithm for Target Localization using Multiple FMCW Automotive Radars (CUM LAUDE)
Vasileios PapanastasiouDeep Learning-based identification of human gait by radar micro-Doppler measurements.
Marc Vizcarro CarreteroA X-Band Patch Antenna Array with Low Cross-pol for Weather Radar Applications (CUM LAUDE)
Guigeng SuDetection of vital signs of auto driver and passengers using (distributed) radars inside auto
Nick CancrinusA Multiple-Input-Multiple-Output (MIMO) grating lobe selection scheme for radar applications (CUM LAUDE)
Sheeraz AhmedMulti-Channel Waveform Agile Radar: Experimental performance evaluation of Advanced Space-Time Adaptive Processing (ASTAP) radar system
Min DingModel-based Interference Mitigation for FMCW Radar System
Alessandro MancinelliPerformances simulation of cooperative small-Sat constellation for synthetic aperture radar imaging
Yefeng CaiRadar Micro-Doppler Patterns for Drone's Characterisation
Elmira KireevaOptimization of the Antenna Placement on a Commercial Aircraft for Communication with Ground and Satellites
Chrysovalantis KladogenisDetection of Wind Turbine Clutter using radar polarimetry
Richard de JongMultimodal Deep Learning for the Classification of Human Activity
2018 Jonathan GnanadhasMicrowave Circuit Analysis of Multi Transmon Qubit System
Shuang ChenMachine Learning Modeling and Parametric Assessment of Rectangular Dielectric Resonant Antenna
Mai-Han TruongFeasibility Study on Optically Transparent Cylindrical Dielectric Resonator Antennas Integrated in an Enclosed Light Bulb Using Doppler Based Radar for Human Presence Detection
Muhammad Omer ZareenDesign and analysis of non-uniform MIMO array for interference suppression and automotive applications
Salman SalmanAnalysis of Antenna and RF Front-End Topologies for Multi-Beam Systems
Eduardo RichaJump Markov Nonlinear System Identification in Multi-Sensor Target Tracking
Jeroen OverdevestInterference in 79 GHz Phase-Coded Automotive Radar
2017 Sasanka SankaRadar to radar interference for 77GHz automotive radar
Ruoyu FengTarget localization using MIMO-Monopulse
Kajeng WangkheimayumDevelopment of Advanced Model of Radar and Communication Signals Scattering on Wind Turbines
Max SchöpeImprovement of Hybrid Codes for MIMO radar using multi-pulse waveforms and signal processing
Kavish IshwardatRadar based horizontal wind profile retrieval techniques: DFT applied to scanning Doppler radar measurements.
Yalin GurcanSuper-resolution algorithms for range-azimuth-Doppler estimation in automotive radars.
2016 Nannan ChenMillimetre wave propagation and scattering phenomena for automotive radar.
Wilco TempertDesign of a particle filter for robust target tracking in object-induced clutter
Jeroen KeijsersDensity Tapering for Sparse Planar Spiral Antenna Arrays
Michael HambalisReduction of Mutual Coupling and Influencing the Antenna-Element Pattern in Array Environment
Roeland TrommelAn Analysis of Deep Learning for Human Gait Classification in Radar
Roel BernsExploiting the micro-Doppler effect for detection improvement in FMCW radar
Yanki AslanReduction of Mutual Coupling Between Closely Spaced Patch Antennas Using Dielectric Contrast Techniques
Joris DerksenA study of radar performance assessment accuracy sensitivity to the resolution of atmospheric input data. Case studies of North Sea environments.
2015 Rossiza GourovaTheory and Practice of Waveforms for Compressive-Sensing Radar
M. WangUltra wideband omnidirectional discone antenna for WLAN applications
Yiou ZhouRadar Doppler Polarimetry of Wind Turbines using the S-band PARSAX radar
2014 Jacco SchreudersTracking aircraft with the PARSAX radar
2013 Sowmini KadathanadWaveform Generation for a MIMO Radar
Paraforou VasilikiDesign and full-wave analysis of supershaped patch antennas
Jason MensinghDevelopment of a Two-Dimensional Resonator Design Tool
Boris Radeljić-JakićDevelopment of Processing Algorithms for the Detection and Estimation of Multi-Layered Structures of a Windfield with Polarimetric Doppler Weather Radar
Maarten KasteleinAircraft Separation Assurance Using Implicit Maneuver Coordination: Issues and Potential Solutions
Ranish Baboeram Panday4D Trajectory De-Confliction For Future ATM By Applying Constraints
Temitope AgbanaModel-based Wavelength Estimation with Tunable Color Filter and Single Photodiode
2012 Joep WezelAssessing the MR compatibility of dental retainer wires at 7 tesla
Paul de HeerHomogeneous RF Field Distribution Optimization in 3T Abdominal Imaging
Netsanet TessemaNode Selection Technique for Distributed Beamforming in Green Cognitive Radio Networks
Vedaprabhu BasavarajappaDesign of a wideband conformal array antenna system with beamforming and null steering, for application in a DVB-T based passive radar
V. SridharanInterference cancellation techniques for low power wireless sensors
Leonardo CarrerConcealed Weapon Detection: a microwave imaging approach
Tom VerboonExploring Opportunities for an Evolutionary Integration of Level 3 UAV Situation Awareness Support into ATC/C2 systems
Eugenio PasquaUWB FMCW Radar for Concealed Weapon Detection: RF front-end development
2011 Stephan GrootModel-based Classification of Human Motion: Using a Particle Filter Approach
Prasetiyono Hari MuktiA Study On Wavelet Packet Based Algorithm For Representation of Wireless Channel
Rahmat MulyawanSynchronization Methods for Wavelet Packet Multicarrier Modulation
Wahyu Adhi PrasetyoRelay Selection and Resource Allocation in Cooperative Wireless Communication Networks
Anurag BajpaiChannel Equalization for Wavelet Packet Modulation
J. ChenA Study on Frequency Dependency and Spatial Modeling of Wireless Channels
2010 Berna TorunPeak-to-Average Power Ratio Reduction Techniques for Wavelet Packet Modulation
W.M. BrinkNon-Invasive Electromagnetic Ablation of Female Breast Tumors
Hossein AzodiUWB Air-Coupled Antenna for Ground Penetrating Radar
H.G. PoleyGPR Antennas Design and Experimental Evaluation
G. BerghuisSimulation of a Detect and Sense System
Nadia HaiderUWB Antenna Design for Polarimetric Imaging Radar
2009 F.W. Van den DungenAn airborne human machine interface for 4D-trajectory based operations - A study of needs for the A30X HMI in the ATM target concept of 2020 described by SESAR
Dony ArianandaOn Wavelet Based Spectrum Estimation for Dynamic Spectrum Access
Aman Miesso BokiyeRay-based Propagation Modeling for OFDM-based Mobile Networks
Iman Ghaseminezhad MarandiInterference Analysis, Measurements and Performance Evaluation of IEEE 802.11n in the presence of other IEEE 802.11b/g/n WLANs
2008 A. Shenario EzhilMillimeter-Wave UWB Antenna Design in LTCC Technology
MSP 2011 R. ZhijieThe Stopping Set Property and the Iterative Decoding Performance of Binary Block Codes on BSC and AWGN Channel
S.P. SathyanarayananA Study of Joint Network Coding and Power Control in Energy Harvesting Networks
2009 H. WangNetwork Coded Flooding
NAS 2015 I.P. StankusAssessment of Dynamic Spectrum Allocation in Realistic Mobile Networks
A.A. Mendoza MartinezVirtual Sectorization in Future Mobile Networks: System-Level Assessment and Optimization in a Realistic LTE Network
C. ChenEpidemic Mitigation via Awareness Propagation in Multi-layer Network
A.K. DziwornuTowards Real-Time Power Restoration Using a Hybrid Genetic Algorithm
M.P.V. ManthenaNetwork-as-a-Service Architecture with SDN and NFV: A Proposed Evolutionary Approach for Service Provider Networks
2014 S. Knappstein-HamelinkNetwork Discovery in a Recursive Internet Network Architecture
2013 V.N. GourovNetwork Monitoring with Software Defined Networking: Towards OpenFlow network monitoring
2012 N.L.M. Van AdrichemTowards a global implementation of Named Data Networking
B. W. AbegazControl Architecture and Utility Maximization for a Smart Grid based Energy Community
S. MathewLTE Performance Measurement In Trial Network & Validation Of LTE Performance Estimation Models
K. CharalampidouEstimating popularity by sentiment and polarization classification on social media
2011 M. NoordermeerImplementing Link-state Update Policies for Quality of Service Routing
B. ShirmohamadiSelf-Optimized Resource Allocation in ICT Systems
A. CaluDragon-Lab, network states detection and identification framework: performance investigation
E.D. AyeleAnalyses and deployement of the BitTorrent protocol for community ad hoc networks
Y. KocQuantitative Modeling of Domain Name System Protocol
2010 R.M.A. ImamdiRobustness Analysis and Capacity Management of the KPN (PS) Mobile Core Network
D. MaheshwariRobust Offshore Networks for Oil and Gas Facilities
2009 J. WuEvolving Properties of Growing Networks
R.A.P. JuffermansDiverse routing in SRLG networks
C. SimmondsTelecom Sector Modelling from a Functional Perspective
RSE 2012 M. Van den OeverSpace-Based FMCW SAR Systems
A. ArgyrouliThe impact of droplets clustering on the radar backscattering from water clouds
2011 J.M.M. VerzeilbergCoherent Multistatic Radar Imaging
M. Vosooghi DizajiScattering in Water Clouds: The Impact of the Spatial Correlation of Particles on The Backscattered Mean Power
2010 S. GeorgiouEstimation and assessment of differential and specific differential phase with the IDRA X-band Doppler polarimetric radar
SPS 2021 Yanbin HeAdaptive Graph Partition Methods for Structured Graphs
2020 Maosheng YangAdvances in Graph Signal Processing
2019 Vishnu RachuriSpace-Time Codes for Massive MIMO Systems
Kevin van der MarkBlind OFDM Signal Parameter Estimation
Bart de VosGradient Coil Design and Construction for a Halbach Based MRI System
Ming DaiInvestigation on Time-of-Arrival Estimation for the LoRa Network
2018 Feng MaRespiration monitoring based on information fusion from Impedance pneumography and electrocardiography
Lichen YaoBluetooth Direction Finding
Aulia Recky SoepenoPhase Domain Ranging for Narrowband ISM Radio Bands
Dennis van der GeestBlind Signal Identification
2017 Xuyang LiSemi-Controllable Compression Schemes for Ultrasound Imaging
2016 Tariq SaboeraliEnhancement of the Spatial Resolution for the Temperature Sensing System of the 7 Tesla Magnetic Resonance Imaging Scanner
Yiling ZhangChina Digital Radio (CDR) Receiver Design and Development with FM Interference Cancellation
2015 Hongrun ZhangSensor Selection and Bit Allocation in WSNs with Realistic Digital Communication Channels
Shailja ShuklaGSVD based blind-beamforming technique for suppression of partially overlapping Bluetooth data packets from WiFi signals
Ruijie ZhangCompressive Power Spectrum Estimation: Further study on Non Uniform sampling and Parametric Approach
Shilpa RaoSparse Arrays: Vector Sensors and Design Algorithms
Yun WangSoftware-defined radio receiver design and development for China Digital Radio (CDR)
2014 Samira BahramiNon-Intrusive Appliance Load Monitoring using the Viterbi Algorithm (NIALM-VA)
Shahrzad NaghibzadehIndoor Granularity Presence Sensing and Control Messaging with an Ultrasonic Circular Array
Joost GeelhoedJoint Angle-Frequency Estimation for Multiple Signals with Circular Arrays
Yongwei WangIndoor Localization based on Room Impulse Response Fingerprinting with little human intervention
Yi LuA "Transmission Time Reservation" method in a Wireless Lighting Control System
Cong NieResearching the BLE based intelligent lighting control system
Keke HuCompressive Sensing for Near-field Source Localization
Ning PanOffline Power Allocation and Spectrum Sensing Strategy in Energy-Harvesting Cognitive Radio Networks
2013 Jason MensinghDevelopment of a Two-Dimensional Resonator Design Tool
Viktor StoevPhotoacoustic Imaging by Means of Sparsity Regularization
Apostolos KontakisSpace-varying FIR filter design for nonuniformly sampled seismic data
Siavash ShakeriUnderwater ultra-wideband fingerprinting-based localization
Jeroen van GemertImaging of Cracks and Weak Spots in Steel and Aluminium Plate Rolls
Lyubomir ZegovWaveform Optimization for Compressive-Sensing Radar Systems
2012 A. RamkumarTransmitter measurements and analysis of frame synchronization of an Impulse Radio Ultra-wideband system
D. Shastry RavishankarBPSK Based Super Regenerative Receiver
Rakshith JagannathGrid Mismatch in Sparse-Signal Recovery of Compressive Sensing
2011 Z. HuangMulti-Carrier Wakeup Radio Receiver
Sundeep ChepuriWideband spectrum sensing techniques for wireless sensors
Millad Mouri SardarabadiComplex Factor Analysis
Stefan KokA multi-lag/multi-scale receiver for underwater acoustic communications
2010 Maxim VolkovRadio frequency detection and mitigation for LOFAR telescope system
A.D. VisserNoise Analysis of an Ultra Wide Band FMCW Ranging Receiver
David CaicedoIllumination control of an LED lighting system based on localized occupancy
Deheng LiuMultiuser Detection for Sensing Asynchronous LED Illumination Contributions
2009 Shahzad GishkoriCompressive Sampling for PPM and FSK Modulated Signals
M.N. KhanAntenna Beamforming for a 60 GHz Transceiver System
Sajit AqeelA noise subspace approach for localization
A.O. AdejuwonCognitive Radio in a Regulatory Environment
Bruhtesfa GodanaHuman movement characterization in indoor environment using GNU radio based radar
Yukang TuWavenumber-frequency spectrum estimation of ambient seismic noise
Zixia HuReceiver Windowing Design for Narrowband Interference Mitigation in MB-OFDM UWB System
THZ 2022 Leila GottmerA GO/PO tool for synthesizing shaped multi-surface dielectric lens antennas
Junhong GuTime-Domain Electromagnetic Leaky Waves Radiation from a Long Slot
Martijn HuiskesTowards the design of an imaging setup using photoconductive antennas
Rik BokhorstMMIC packaging using Flip-Chip technology at G band
Jinglin GengVolumetric Method of Moments: A Numerical Tool for High Frequency Problems Analysis
Caspar Coco MartinWideband Flat Lenses Based on Artificial Dielectric Layers
Dunja LončarevićSpectral Analysis of The Infinite Slot Leaky Wave Antenna & Leaky Wave Antenna With Multiple Slots
2021 Zhuang ChenWideband Feeding Network Design For Dual-Polarized Connected Arrays
Ashwita NairGeometrical Optics - Physical Optics model of the mutual coupling between antennas under integrated lenses
Saurabh NerkarGUI for System Dimensioning and QO Channel Analysis of Pulsed Pico-second Radar
Nina Beschoor PlugDesign and Implementation of a Superconducting Phase-Shifter
Caspar van WamelReduction of Cross Polarization Level in Connected Slot Arrays using Artificial Dielectric Layers with Vertical Metallic Inclusions
Nick van RooijenOn the Development of a Lens Phased-Array at 100GHz
Stefanie BrackenhoffSPLITTER: A data model and algorithm for detecting spectral lines and continuum emission of high-redshift galaxies using DESHIMA 2.0
2020 Antonios PelekanidisA THz Lens Antenna fed by a Photoconductive Connected Dipole Array
2019 Cyrus Tirband DastgerdiA non-galvanic chip-to-waveguide transition for mm-wave characterization probes
Alexander van KatwijkDesign of a Wideband Wide-Scan Connected Slot Array Antenna Using Artificial Dielectrics
Kevin KouwenhovenDielectric Loss Measurements at Sub-K Temperatures and Terahertz Frequencies
2018 Huasheng ZhangA GO/FO Tool for Analyzing Quasi-optical Systems in Reception
Bart van den Bogert28 nm CMOS Array of Strips for Pedestrian Detection
Diego EmerEM Interference Analysis of the Fly's Eye Antenna System in Stadium Scenarios
2017 Zhengzheng WangComplete tool for predicting the mutual coupling in non-uniform arrays of rectangular aperture radiators
Ralph van SchelvenAnalysis of three dimensional array antenna elements to achieve asymmetric active element patterns
Cantika FelitaAnalytical Study of Artificial Dielectrics Composed of Non-Aligned Layers
Sjoerd BosmaQuasi-optical system for the DESHIMA spectrometer
Arturo Fiorellini BernardisThe Observable Field: On the Estimation of the Available Power for Antennas in Reception
2016 Alejandro Pascual LagunaEarly design of the MOSAIC antenna
2015 Shahab DabironezareAnalysis and design of a dual-band THz imager based on incoherent detectors.
Siyi ZhouAnalysis and Design of Pulsed Photoconductive Antennas
Wenda ZhuMm-Wave In-Package Antennas for Short-Range Car Radar Application
Xuxiang LiuDemonstration of 2 x 2 heterodyne receiver array at 1.4THz using HEB mixers and Fourier phase grating LO
Sven van BerkelCharacterization of Printed Transmission Lines at High Frequencies
2014 Harshitha Thippur ShivamurthyWideband, Wide-Scan Planar Connected Slot Array Enhanced with Artificial Dielectrics
2013 Vincent VoogtLoop-to-Loop Pulsed Electromagnetic Field Signal Transfer in Layered Configurations: Application to Inter-Chip Wireless Communication
MS3 2016 Wilfred BoelhouwerA Reconfigurable Antenna based on a Non-radiative Dielectric Waveguide with a Liquid Crystal Dielectric
THZ 2019 Andrea DegasperiTime Domain Modeling of Photoconductive Antennas