Understanding Duplexers

Duplexers are three port RF devices that allow a closely spaced transmitter and receiver to share a single antenna. This video provides a short technical introduction to duplexers, how they are constructed, and how their most important parameters are measured.

Understanding S-Parameters:    • Understanding S Parameters  

Understanding Filter Measurements:    • Understanding Filter Measurements  

Vector Network Analyzers from Rohde & Schwarz: https://www.rohde-schwarz.com/us/prod...

Test and Measurement Fundamentals Playlist:    • Test & Measurement Fundamentals  

Timeline:
00:00 Introduction
00:14 Suggested viewing
00:37 About duplexers
02:01 Duplexer construction
02:55 Duplexer form factors
03:29 Band reject (Br) / notch filters
04:16 Drawbacks of a notch-only duplexer
05:21 Bandpass (Bp) filters
06:52 Combined bandpass and band-reject duplexer
07:43 Aside: about duplexer tuning
08:52 About duplexer measurements
09:46 Common duplexer measurements
10:07 Attenuation
11:15 Example attenuation measurement – Br only duplexer
12:14 Example attenuation measurement – Br / Bp duplexer
13:12 Example attenuation measurement – Br / Bp duplexer (alt.)
14:02 Isolation
15:02 Example isolation measurement
15:41 SWR / return loss
16:42 Example return loss measurement
17:23 Duplexer vs. diplexer
18:54 Summary