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--- user:kurser:ham_vt2023_l7 [2023/02/24 18:43] – user
+++ user:kurser:ham_vt2023_l7 [2023/04/11 08:44] – user
@@ Line 3: / Line 3: @@
 [[user:kurser:ham_vt2023|Back to course information]]
-Recommended reading: KonCEPT page 191-229 (chapter 7 + 8)
+**Recommended reading: KonCEPT page 191-229 (chapter 7 + 8) **
 Start with transmission line (TL), the most difficult component.
@@ Line 25: / Line 25: @@
 ==Antennas==
-Show some example antennas.
+Antenna = two port that converts energy from propagating in a transmission line to propagation in free-space.
-  * Ground plane/verticals
-  * Loop antennas
+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
-  * log periodic
+  * Quad
-  * Parabolic
+  * Patch
-  * etc.
+  * Bowtie
+  * PCB/PIFA
+  * Spiral/Helical
 Talk about polarization.
@@ Line 80: / Line 96: @@
 Fading example with cellphone if possible
+Radio Antenna Fundamentals Part 1 1947
+https://www.youtube.com/watch?v=JHSPRcRgmOw&ab_channel=GerryTrenwith