Antenna Radiation Pattern Measurement System

Importance of Understanding Antenna Radiation PatternsMeasurement TechniqueSystem OverviewSystem ProgrammingMeasurement ProcedureResults

Antenna Radiation PatternsRoadmap for Antenna Designers

Quick picture of antenna overall response

Selection of the antenna for the improved system performance

Optimization of antenna for specific applicationE-Plane Pattern of a DipoleH-Plane Pattern of a Dipole

Measurement TechniqueSingle-Axis-Rotation Technique

Transmitter SetupReceiver SetupPositionerPlotterMeasurement SystemHP8753C Network AnalyzerTransmitting AntennaLaptopHP8561A Spectrum AnalyzerReceiving AntennaComputerAT6250 Servo ControllerServo Motor

Measurement SystemHP8753C Network AnalyzerServo MotorHP8753C Spectrum AnalyzerAUTLaptopGPIBAT6250 Servo Controller BoardComputerTo Serial Port (pin 8)

System ProgrammingPositioner Programming (Motion Architect)LabVIEW Programming

Positioner Programming (Motion Architect)Rotate the antenna under test (AUT) 360, with an increment of 1 per step.

Generate a High and a Low signal at the OUTPUT terminal of the AT6250 Servo Controller board for every 1 increment.

LabVIEW ProgrammingAcquire signal strength of the AUT from Spectrum Analyzer (Block 1)

Monitor the High and Low signal at AT6250 servo controller board (Block 2) Generate the angular position of the AUT and plot the radiation pattern (Block 3)

SynchronizationHigh (5 V)Low (0 V)2 SecAT6250 OUTPUTLabVIEW Signal Strength of the AUT from Spectrum AnalyzerAngular Position of the AUT12336012 3 360 Acquire Data

Measurement ProcedureTransmitter ConfigurationReceiver ConfigurationAlignment of Tx and Rx AntennasLabVIEW ConfigurationCompumotor ConfigurationPlanePolarization

Tests and ResultsDipole (500 MHz)UWB AntennaOmni Directional AntennaHorn Antenna

Dipole Antenna Designed at 500 MHz but operated at 1.43 GHzMeasured E- Plane PatternTheoretical E- Plane PatternTransmitting HornDipole (AUT)

UWB Radio AntennaMeasured H-Plane Pattern Reverse Bow-Tie Antenna operated at 2.4 GHzTransmitting HornReverse Bow-Tie Antenna

Omnidirectional AntennaMeasured E-Plane PatternTheoretical E-Plane PatternMeasured H-Plane PatternTheoretical H-Plane PatternTransmitting HornOmni Directional Antenna

Horn AntennaMeasured E-Plane PatternTheoretical H-Plane PatternTransmitting and Receiving Horn Antennas