user:kurser:ham_vt2023_l8
ETA313-08 Lab 2: Build an antenna
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
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
user/kurser/ham_vt2023_l8.txt · Last modified: 2025/02/16 10:13 by user