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=====ETA313-08 Lab 2: Build an antenna	=====

[[user:kurser:ham_vt2025|Back to course information]]

Agenda: ETA to construct antennas at ETA. 

Go and search for DIY antennas online!

===The following theory is copied from Theory Lesson 3: Antennas, Transmission lines, Propagation ===

[[user:kurser:ham_vt2023_l7|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