Waveguide - T AE-323 MICROWAVE DEVICES AND ENGINEERING Lecture No 07 Text Book : Microwave Devices and Circuits by Liao Chapter 4 Section 4-4-1 Instructor: Engr Irfan Ahmed Class: Avionics 6 (Batch 2) Number of Slides: 19 Avionics Engineering Department

Learning Objectives Types of Waveguide T’s E-plane T H-plane T Magic T

Types of Waveguide T’s E-plane T H-plane T Magic T

E-plane Tee Axis of side arm is parallel to the E-field of the main guide. If E-plane T is perfectly matched: If the side arm is the input port:

E-plane Tee

E-plane Tee If Input is at port 3 , then Output at port 1 & port 2 is same but out of phase So As per symmetricity property

E-plane Tee Unitary property Multiplying Suppose port 3 is matched

E-plane Tee Subtracting the equations We get

E-plane Tee Now matrix will result from To

E-plane T (Series T) http://www.rfcafe.com/references/electrical/NEETS-Modules/NEETS-Module-11-1-51-1-60.htm

H-plane T (Shunt T) Axis of side arm is perpendicular to the E-field of the main guide. If the side arm is the input port:

http://www.rfcafe.com/references/electrical/NEETS-Modules/NEETS-Module-11-1-51-1-60.htm

Magic T (Hybrid T) If two waves of equal magnitude and same phase are fed into port 1 and port 2 output will be zero at port 3 and additive at port 4. If a wave is fed into port 4 (H arm), it will be divided equally between port 1 and port 2 of the collinear arms and will not appear at port 3 (E arm).

Magic T (Hybrid T) If a wave is fed into port 3, it will produce an output of equal magnitude and opposite phase at port 1 and port 2. the output at port 4 is zero. That is, S43 = S34 = 0. http://www.rfcafe.com/references/electrical/NEETS-Modules/NEETS-Module-11-1-51-1-60.htm

Magic T (Hybrid T) If a wave is fed into one of the collinear arms at port 1 or port 2, it will not appear in the other collinear arm at port 2 or port 1 because the E arm causes a phase delay while the H arm causes a phase advance. That is, S12 = S21 = 0. http://www.rfcafe.com/references/electrical/NEETS-Modules/NEETS-Module-11-1-51-1-60.htm

Magic Tee They are used in mixing, duplexing Example two identical radars transmitters requires Twice more input to the Antenna than Either transmitter can deliver

2 Transmitter Example

Summary