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Agenda: ETA to construct antennas at ETA.

Go and search for DIY antennas online!

ETA313-07

Antenna = two port that converts energy from propagating in a transmission line to propagation in free-space.

Characterized by:

• Input impedance, SWR, Z_in
• Operation frequency, resonance frequency, f_0
• Directivity D, antenna gain, dBi, dBd
• far field distance = d_f > 2*D^2/lambda, given d_f » D, d_f » lambda
• Radiation efficiency, eta
• radiation pattern, E & H patterns
• Polarization and x-pol suppression and so on…

We can only measure input impedance and operational frequency easily with a VNA/Antena analyzer … so lets do that at ETA.

Different types

• Dipole
• Monopole
• Small loop
• Yagi
• Quad
• Patch
• Bowtie
• PCB/PIFA
• Spiral/Helical