Module 02: Starlink RF Foundations and Phased-Array Access Links

Phase: 1 - Foundation Builds on: Module 01

Math You’ll Learn

Algebra 2 Completion + Trigonometry Introduction

You will finish the Algebra 2 pieces needed for RF calculations and begin trigonometry, the math used for satellite visibility, phased-array steering, and handover timing.

• Sequences and summation notation - time-series link quality, telemetry samples, and scheduler history.
• Unit circle, sine, cosine, tangent - the foundation for beam direction and satellite geometry.
  • Starlink application: user-terminal beam steering and satellite look angles.
• Inverse trig functions - compute angles from known distances and vectors.
  • Starlink application: elevation and scan angle from terminal to satellite.
• Frequency and wavelength relationship - lambda = c/f.
  • Starlink application: antenna size, gain, and beamwidth depend on wavelength.

After this: You can reason about Starlink access-link geometry, why phased arrays are required for LEO broadband, and how slant range drives delay and path loss.

Resources:

• Khan Academy - Algebra 2 sequences and Trigonometry intro
• Pratt, Satellite Communications, propagation and frequency-band chapters
• Starlink Technology - phased-array and low-latency architecture overview

What You’ll Learn

This module refocuses generic space communications into Starlink’s access-link model: moving LEO satellites, electronically steered user terminals, Ku/Ka/E-band links, and rapid handover.

Starlink RF Access Model

• Ku-band service links between user terminals and satellites.
• Ka/E-band feeder links between satellites and gateways.
• TT&C links as operational context, separate from broadband traffic.
• Link categories: user service link, feeder/gateway link, inter-satellite link, and management/telemetry.
• Why LEO reduces propagation delay but forces constant tracking and handover.

Phased-Array Antenna Concepts

• Beam steering, beamwidth, scan loss, sidelobes, aperture, gain, and polarization.
• Electronically steered arrays vs mechanically steered antennas.
• Why flat-panel user terminals matter for moving LEO satellites.
• Beam switching and preserving user sessions at the system level.
• Publicly known behavior vs inferred scheduler/PHY behavior.

Link Concepts

• FSPL vs frequency and range.
• Modulation/coding only at the level needed now: MCS, LDPC, OFDM/OFDMA/TDMA trade-offs.
• Spectrum coordination, interference, and FCC/ITU constraints.
• Doppler as a preview topic; the full math arrives later.

C++ and Python Skills

C++ focus: control flow, functions, basic classes, constructors, enums, formatted output.

Python focus: NumPy arrays, matplotlib plotting, simple geometric visualization.

Projects

Project 1: Starlink Delay and Path-Loss Calculator (C++)

Build a CLI tool for Starlink-like LEO link estimates.

What you’ll build:

• Represent orbit altitude, frequency band, and terminal/gateway link type with enums/classes.
• Compute one-way delay and RTT from slant range.
• Compute FSPL for Ku, Ka, and E-band examples.
• Print comparison tables for low-elevation, mid-elevation, and near-overhead passes.
• Keep assumptions configurable and documented.

C++ skills used: functions, classes, enums, <iomanip>, command-line arguments.

Toolkit: Add AccessLinkModel foundations.

Project 2: Phased-Array Beam Geometry Plotter (Python)

Visualize how terminal look angle affects link quality.

What you’ll build:

• Plot scan angle, elevation, estimated scan loss, and slant range over a satellite pass.
• Show visible satellite intervals for a fixed user terminal.
• Compare low vs high elevation masks.
• Annotate where handover would likely be preferred based on geometry.

Python skills used: NumPy, matplotlib, simple trigonometric models.

Technology Reference

Where This Tech Is Used

Books and Resources