Node Antenna Types, Use Cases, and Deployment Configurations

The system supports three antenna classes: phased-array (primary), motorized parabolic, and fixed. This document summarizes deployment characteristics and antenna selection criteria.

1. Phased-Array Antenna (Primary Configuration)

Characteristics:

• 8-16 element arrays with λ/2 spacing
• Electronic beam steering (no moving parts)
• Slew rate: 10-50°/second (FPGA-limited)
• Gain: 15-20 dBi
• Beamwidth: 2-3°
• Frequency range: 4.5-5.5 GHz (C-band)

Deployment use:

• Primary choice for rocket telemetry
• Low latency (100 us weight updates)
• 360° azimuth coverage without mechanical slew

2. Motorized Parabolic Antenna

Characteristics:

• 3-4 meter dish diameter typical
• Motor-driven azimuth/elevation
• Slew rate: 1-10°/second (motor-limited)
• Gain: 25-30 dBi
• Beamwidth: 1-2°
• Frequency range: 4.5-5.5 GHz

Deployment use:

• Alternative for fixed-base operations
• Higher gain and tighter beamwidth than phased-array
• Slower steering limits trajectory tracking

3. Fixed-Position Antenna (Low-Complexity Configuration)

Characteristics:

• Fixed mechanical position
• No actuation or motors
• Gain: 10-15 dBi typical
• Beamwidth: 5-10°
• Frequency range: 4.5-5.5 GHz

Deployment use:

• Fallback for simplified operations
• Lab testing and known targets only
• No pointing control (frequency tuning only)

4. Hybrid Configurations

Possible but operationally harder:

• Phased-array with optional motorized secondary dish (dual-mode)
• Motorized with phased elements in aperture (sub-array steering)

5. Antenna Selection Decision Tree

1. Is pointing control required?
   NO  → Fixed antenna
   YES → Continue

2. Is fast steering (<1 second) needed?
   NO  → Motorized (10+ meter site OK)
   YES → Phased-array (compact)

3. Is gain critical (weak signal)?
   NO  → Phased-array (sufficient 20 dBi)
   YES → Motorized (30+ dBi possible)

4. Can you operate phased-array?
   NO  → Motorized fallback
   YES → Use phased-array  (primary choice)

Related: See Node-AntennaAbstraction for control abstraction, and System-EndToEnd for system-level antenna diversity.