Attachment Spec Report

This document pretains to SAT-PDR-20180910-00069 for Petition for Declaratory Ruling on a Satellite Space Stations filing.

IBFS_SATPDR2018091000069_1526603

    FEASIBILITY REPORT ON VARIOUS 400 MHZ RHCP ANTENNA CONFIGURATIONS




                                                                                                 July 24, 2017




Specification Report on 400 MHz Antenna


Contents
1     Specification ....................................................................................................................... 3
2     Single QHA directed at the Nadir ........................................................................................ 3
            Geometry of a single QHA ........................................................................................... 3
            3D View of the Right Hand Circular Antenna Pattern ................................................... 4
            3D antenna pattern along X and Y axis ........................................................................ 4
            2D Polar View, showing Max RHCP Gain is >4.6 dBirhcp ............................................ 5
            Rectangular view showing -3 dBi Beamwidth of 120Deg.............................................. 5
            Gain vs Frequency shows 4.6 dBiRHCP gain at 400 MHz ........................................... 6
            Smith Chart .................................................................................................................. 6
3     Single QHA Recessed 30 mm into 6U Cube Sat ................................................................. 7
            Geometry of 30mm Recessed QHA ............................................................................. 7
            3D View of the Right Hand Circular Antenna Pattern ................................................... 8
            3D ant pattern along X axis, in YZ plane ...................................................................... 9
            3D ant pattern in YZ plane ........................................................................................... 9
            2D Polar Elevation View, Y axis, in XZ plane ..............................................................10
            Rectangular view showing -3 dBi Beamwidth of 107 Deg............................................10
            Gain vs Frequency showing 4.6 dBiRHCP gain at 400 MHz .......................................11
            Smith Chart .................................................................................................................12
4     2nd Harmonic Response for Single QHA Recessed 30 mm into 6U Cube Sat ....................13
5     3rd Harmonic Response for Single QHA Recessed 30 mm into 6U Cube Sat ....................14




Helical Communication Technologies                                         July 30, 2017                                Page 1 of 14


 FEASIBILITY REPORT ON VARIOUS 400 MHZ RHCP ANTENNA CONFIGURATIONS

The antenna presented herein are feasible to construct. These are deployable antennas. The
antenna bifilar loops are constructed using NiTinol wire. These bifilar loops are situated on a
printed wiring board. The capacitor and inductor components are realizable; that is, they are of
practical values. The NiTinol construction allows the antenna to be stowed within the cube sat
structure. After launching into Low Earth Orbit, the antenna may be deployed by applying an
electrical direct current. HCT advocates use of a High Efficiency Voltage Regulator with Current
Limiting circuit placed on the underside of the antenna PCB. Recent measurements
recommend a current limiting circuit at about 4 amperes. The Voltage floats from about 3 to 5
volts. The power is applied for about 60 seconds. The antenna deployment benefits from solar
heating in Low Earth Orbit.


We look forward to working with Magnitude Space to develop a Quadrifilar Helical Antenna
suited to your desired specifications.


Gregory O’Neill, Chairman
Helical Communication Technologies
634 Barnes Blvd
Rockledge, FL 32955
(321.208.8978)
greg@HCTemail.com
http://HeliComTech.com




Helical Communication Technologies                 July 30, 2017                  Page 2 of 14


 FEASIBILITY REPORT ON VARIOUS 400 MHZ RHCP ANTENNA CONFIGURATIONS




1 Specification

This report presents a Specification Report for a Single Quadrifilar Helical Antenna. The
Feasibility Study results have shown that a single Quadrifilar Helical Antenna really is the
practical way to proceed. It offers a nearly uniform X axis and Y axis footprint on earth below
the satellite.

The report establishes performance of a Single QHA on a 100x100mm ground plane as a
baseline.
For the graphs that follow, +X is pictured as the forward direction of the spacecraft and -Z is the
nadir. It is important to be aware of the orientation of the antenna and 3D views. The orthogonal
views of the antenna pattern and gain vs frequency graphs are plotted with respect to origin.
The rectangular view shows the beamwidth in the nadir.


Gain directed at the nadir: Greater than +4 dBiRHCP
Beamwidth mounted on 6U ISIS Cube Sat structure: Between 110 and 120 Degrees




2 Single QHA directed at the Nadir

      Geometry of a single QHA




Helical Communication Technologies                   July 30, 2017                  Page 3 of 14


 FEASIBILITY REPORT ON VARIOUS 400 MHZ RHCP ANTENNA CONFIGURATIONS

Axial Ht = 286 mm Prox Dia = 75 mm Dist Dia 35.5 mm Pitch.Angle = 58 Deg
Cseries = 15 pF Lshunt = 8 nH Lmatch = 62 nH Cbalun = 6.6 pF Lbalun = 18.5 nH
                The single QHA by itself is an appropriate reference antenna


     3D View of the Right Hand Circular Antenna Pattern




                  Maximum RHCP Gain = 4.6 dBirhcp, Orthographic View


     3D antenna pattern along X and Y axis




                              Maximum RH Gain = 4.61 dBi
              These graphs show symmetrical X and Y axis performance.




Helical Communication Technologies               July 30, 2017                 Page 4 of 14


 FEASIBILITY REPORT ON VARIOUS 400 MHZ RHCP ANTENNA CONFIGURATIONS


    2D Polar View, showing Max RHCP Gain is >4.6 dBirhcp




  This view is in the Y axis, in the XZ plane. The background is scaled in 2 dBi increments.


    Rectangular view showing -3 dBi Beamwidth of 120Deg




  This view is in the Y axis, in the XZ plane. The background is scaled in 2 dBi increments.




Helical Communication Technologies                July 30, 2017                  Page 5 of 14


 FEASIBILITY REPORT ON VARIOUS 400 MHZ RHCP ANTENNA CONFIGURATIONS


    Gain vs Frequency shows 4.6 dBiRHCP gain at 400 MHz




    SMITH CHART




       The antenna is matched well over the 5 MHz bandwidth centered on 400 MHz.




Helical Communication Technologies            July 30, 2017                Page 6 of 14


 FEASIBILITY REPORT ON VARIOUS 400 MHZ RHCP ANTENNA CONFIGURATIONS


3 Single QHA Recessed 30 mm into 6U Cube Sat

     Geometry of 30mm Recessed QHA




 The recessed distance of the antenna into the structure affects the antenna pattern. This case
  uses a 100x100x10 Grid, representing the Printed Circuit Board the antenna is mounted on.


Axial Ht = 293 mm Prox Dia = 75 mm Dist Dia 35.5 mm Pitch.Angle = 56 Deg
Cseries = 270 pF Lseries = 4 nH Lshunt = 50 nH      Cbalun = 7.7 pF Lbalun = 4.6 nH


HCT is in the process of changing to use the High Frequency Structure Simulator. The main
improvement is likely to be in the printed circuit board impedances. Therefore, the capacitor
and inductor values are likely to change.




Helical Communication Technologies                  July 30, 2017                 Page 7 of 14


 FEASIBILITY REPORT ON VARIOUS 400 MHZ RHCP ANTENNA CONFIGURATIONS




     3D View of the Right Hand Circular Antenna Pattern




Maximum RHCP Gain is 4.6 dBi


Orthographic View.


The antenna recess mounted in the Cube Sat structure 30 mm indicates 0.2 dB decrease over
                                  the antenna by itself.




Helical Communication Technologies             July 30, 2017                Page 8 of 14


 FEASIBILITY REPORT ON VARIOUS 400 MHZ RHCP ANTENNA CONFIGURATIONS


     3D ant pattern along X axis, in YZ plane




                                Maximum RH Gain = 4.6 dBi


     3D ant pattern in YZ plane




                                Maximum RH Gain = 4.6 dBi


Note: The XZ and YZ plane views are nearly identical indicating a very symmetrical pattern.




Helical Communication Technologies                 July 30, 2017                 Page 9 of 14


 FEASIBILITY REPORT ON VARIOUS 400 MHZ RHCP ANTENNA CONFIGURATIONS


     2D Polar Elevation View, Y axis, in XZ plane




                               Maximum RH Gain = 4.6 dBi




     Rectangular view showing -3 dBi Beamwidth of 107 Deg




The beamwidth is slightly affected by the cube sat structure. The beamwidth may vary when
the actual antenna is built and placed on the satellite with the solar panels.




Helical Communication Technologies               July 30, 2017               Page 10 of 14


 FEASIBILITY REPORT ON VARIOUS 400 MHZ RHCP ANTENNA CONFIGURATIONS


     Gain vs Frequency showing 4.6 dBiRHCP gain at 400 MHz




                  The gain vs frequency varies 1.1 dB over the 5 MHz band.
The satellite structure and the solar panels affect the antenna pattern and impedance match.
After considerable simulation HCT has determined it will be best to operate the antenna
significantly off maximum gain. This allows the antenna to perform with minimum affects to the
performance compared to an antenna without the satellite structure and the solar panels.




Helical Communication Technologies                 July 30, 2017                Page 11 of 14


 FEASIBILITY REPORT ON VARIOUS 400 MHZ RHCP ANTENNA CONFIGURATIONS


    Smith Chart




             The antenna driving point impedance shows a very good SWR.




Helical Communication Technologies           July 30, 2017                Page 12 of 14


 FEASIBILITY REPORT ON VARIOUS 400 MHZ RHCP ANTENNA CONFIGURATIONS


4 2ND HARMONIC RESPONSE FOR
   SINGLE QHA RECESSED 30 MM INTO 6U CUBE SAT




Helical Communication Technologies    July 30, 2017        Page 13 of 14


 FEASIBILITY REPORT ON VARIOUS 400 MHZ RHCP ANTENNA CONFIGURATIONS


5 3RD HARMONIC RESPONSE FOR
   SINGLE QHA RECESSED 30 MM INTO 6U CUBE SAT




Helical Communication Technologies    July 30, 2017        Page 14 of 14



Document Created: 2017-07-30 12:27:58
Document Modified: 2017-07-30 12:27:58

© 2024 FCC.report
This site is not affiliated with or endorsed by the FCC