Highly efficient monopulse tracking feed subsystem for unmanned aerial vehicle

A monopulse tracking subsystem for unmanned aerial vehicle is described. It is composed of a septum polarizer and a TM01 circular waveguide mode tracking coupler. The tracking coupler utilizes only two parallel slots for sensing TM01 mode which made the system more compact along with a very small size. The whole monopulse tracking subsystem was designed, fabricated and tested for the Ku-band (14.4-15.5). It provides an excellent return loss >; 28dB, an axial ratio better than 0.45dB and an isolation between the sum and the difference signals more than 50dB.