dino communications considerations 3 antenna ideas bent dipole monopole helix timeline

7
DINO Communications Considerations 3 antenna ideas Bent dipole Monopole Helix Timeline

Upload: ann-aubrie-mcdonald

Post on 19-Jan-2016

226 views

Category:

Documents


0 download

TRANSCRIPT

Page 1: DINO Communications Considerations 3 antenna ideas Bent dipole Monopole Helix Timeline

DINO Communications Considerations 3 antenna ideas

Bent dipole Monopole Helix

Timeline

Page 2: DINO Communications Considerations 3 antenna ideas Bent dipole Monopole Helix Timeline

Considerations1. We only have a certain

diameter surface to work with which rules out certain antennas (parabolic, etc.)

2. We will not be able to encase an antenna in the internal structure of the satellite (horn, etc.)

3. Deployment of antennas

4. Budget

Page 3: DINO Communications Considerations 3 antenna ideas Bent dipole Monopole Helix Timeline

Bent Dipole Antenna Characteristics

1.22dB (for this bent dipole simulation), however gain can improve to approximately 7dB.

60 deg x 60 deg (typical half-power beam width, will vary with angle of dipole)

Frequency limits (3MHz to 500MHz)

Linear Polarization

Page 4: DINO Communications Considerations 3 antenna ideas Bent dipole Monopole Helix Timeline

Bent Dipole Antenna Bent Dipole with

increased angle from wave propagation axis (z)

Provided a gain of 4.9dB

As angle was increased from z axis, worked up to a gain of approximately 7dB. However a certain point the dB gain decreased as bent dipole looked more like a dipole

2

Page 5: DINO Communications Considerations 3 antenna ideas Bent dipole Monopole Helix Timeline

Monopole Antenna Characteristics

-18dB gain along z axis and 2.3dB gain along y axis (for this monopole antenna)

45 deg x 360 deg (typical half-power beam width)

No frequency limits Linear polarization

Page 6: DINO Communications Considerations 3 antenna ideas Bent dipole Monopole Helix Timeline

Helix Antenna Characteristics

10dB (typical gain) 50 deg x 50 deg (typical

half-power beam width) 100 MHz to 3GHz

(frequency limit) Circular polarization If used, special attention

will need to be made as to the angle and position of a helix antenna on the satellite.

Page 7: DINO Communications Considerations 3 antenna ideas Bent dipole Monopole Helix Timeline

Timeline1. Rough link power budget

by 11-22. Will help find required gain for our satellite antennas.

2. With gains approximated for satellite antennas, work on design of antennas by 12-6.

3. Write up of full antenna plan containing link power budget and 1st prototype antennas. (?)

Cross Link UnitsTransmitter (Tx)

1 Tx Power, Pt 27.0 dBm Assume: 0.5 Watts2 Tx Component Line Losses, Ltl 1.0 dB (low power mode)3 Tx Antenna Gain (Peak), Gt 0.0 dBi4 Tx Pointing Loss, Ltp 1.0 dB5 Tx Radome Loss, Ltr 0.0 dB

6 EIRP (1-2+3-4-5) 25.0 dBm

PropagationTransmission Frequency, f 144.0 MHzLink Range, R 50.0 km Maximum Propagation Factor, n 1.0

7 Free Space Loss, Ls 109.6 dB8 Atmospheric Absorption, Lpa 0.0 dB9 Precipitation Absorption, Lpp 0.0 dB

10 Total Propagation Loss (7+8+9) 109.6 dB

Receiver (Rx)11 Rx Antenna Gain (Peak), Gr 0.0 dBi12 Rx Polarization Loss, Lrpol 0.0 dB13 Rx Pointing Loss, Lrp 1.0 dB14 Rx Radome Loss, Lrr 0.0 dB15 Rx Component Line Losses, Lrl 1.0 dB16 Rx Implementation Losses, Lri 1.0 dB

17 Received effective carrier power -87.6 dBm(6-10+11-12-13-14-15-16)

Noise18 Standard Thermal Noise, kT -174.0 dBm/Hz19 Rx Noise Bandwidth, W 43.0 dBHz Assume: 20000 Hz20 Rx Noise Figure, NF 5.0 dB

21 Effective Noise Power (18+19+20) -126.0 dBm

Result22 Available CNR (17-21) 38.4 dB23 Data Rate 39.8 dBHz Assume 9600 bps24 Available Eb/No (22+19-23) 41.5 dB25 Implementation Losses 3.0 dB26 Required Eb/No 14.2 dB Assume BER=0.00000125 Margin (24-25-26) 24.3 dB