EC14 · Sem 7 · Antennas & propagation

Uniform linear array and beam steering

Aim: Narrow and steer a beam electronically with an antenna array.

🧪 Live simulation🧊 Real-time 3D bench⚠ Simulated values, not physical measurements

🔬 Virtual lab

Starting the lab…

📘 Theory

N elements spaced d apart multiply the element pattern by the array factor. A progressive phase β between elements steers the main beam without moving the antenna: the principle of phased arrays and 5G beamforming.

AF = sin(Nψ/2)/(N·sin(ψ/2)) · ψ = kd·cos θ + β

🧰 Apparatus (virtual)

Array of N dipoles
phase shifters
pattern display

📝 Procedure

Start with 4 elements at 0.5 λ
Increase N and watch the beam narrow
Change β and watch the beam steer
Set d above 1 λ and spot grating lobes

Observations and result (kept on this device)

🎤 Viva questions

Why must spacing be under one wavelength

Larger spacing creates grating lobes: extra unwanted beams.

Where is beam steering used

Radar, 5G base stations, satellite terminals.

🛡️ Safety

Virtual lab. With real RF equipment, respect exposure limits, never transmit without a licence, and keep antennas away from people.