BeamSteeringonMetersHamSDRAmateurRadio光束转向米hamsdr业余无线电.pptx

2 Element End-Fire ArrayClassic cardioid patternNull aimed up about 20 degrees4 Element Broadside ArrayBidirectional pattern1:1:1:1 amplitude assignment for max directivity4 Element Broadside ArrayBidirectional pattern1:3:3:1 amplitude assignment for no sidelobes8 Element Broadside/End-Fire ArrayProduct of end-fire and 1-1-1-1 broadside patternsEnd-Fire null not as wide as broadside main lobeMany back and side lobes yet max directivity8 Element Broadside/End-Fire ArrayProduct of end-fire and 1-3-3-1 broadside patternsEnd-Fire null not as wide as broadside main lobeLeaves two little back lobes8 Element BS/EF Array SteeredPattern broadens as steered away from normalUsing no-sidelobe 1-3-3-1 feed patternSteered 10 degrees,20 degrees8 Element BS/EF Array Steered IIPattern broadens as steered away from normalPattern degenerates to bidirectionalSteered 30 degrees,40 degrees8 Element BS/EF Array Steered IIIPattern broadens as steered away from normalAfter 60 degrees,secondary lobe becomes biggestSteered 50 degrees,60 degrees8 Element BS/EF Array Numbers8 Element BS/EF Array NumbersRDF Compared to Other AntennasShort Vertical DesignSlightly scaled W8JI short vertical designMore numerous but shorter radialsArray LayoutNorth to the left,Africa is upNeeds more real estate than a BeverageArray of ArraysEach pair(1&5,2&6,etc.)is an end-fire arrayThere are 4 end-fire arrays in phaseEnd-Fire Reversing SwitchDecouples relay power from feedlineFirst transformer inverts signal from east verticalSecond transformer converts 37 to 75Phasing specs from ON4UNs bookBlock DiagramM-Audio Delta 1010LTSoftrock v6 Receivers&DDS 6.0 VFOCalibration is AnnoyingSoftrock input filter very inconsistentAntennas vary despite careful tuningCalibration accommodates inconsistencyUse of off-site signal best calibration strategyIn-shack calibration source seems almost good enoughTypical Screen ContentComputer RequirementsJust a guess based on my computerFaster than 1.5 GHzProbably 512 megabytes RAMPCI slot for the Delta 1010LTSerial or USB to control frequencyHuge hard drive if you want to make recordingsSoftware RequirementsLinux 2.6.18 or laterReal Time patchesJack Audio Connection Kit(JACK)DttSP(see dttsp.org for other requirements)SDR_Shell(ewpereira.org/sdr-shell)My phasing softwareNumerous other packagesEventually I will document installationAdvantagesContinuously steerableOptimal best RDF for the real estateFlexible broadside,end-fire,circle,etc.Panoramic display is built-inMultiple outputs simultaneouslyDisadvantagesSDR versus traditional radio tradeoffs:Latency versus selectivityWide front end versus narrow front endIntegration:not just an antenna,its a radioLack of knobsFuture WorkActive elements facilitates experimentation9 Element circle array5 Element end-fire arrayIntegrate receiving system with transmitterTransmit beam steering