3-72K1 D
What type of antenna pattern is radiated from a ground station phased-array directional antenna when transmitting the PPM pulses in a Mode S interrogation signal of an aircraft's Traffic alert and Collision Avoidance System (TCAS) installation?
A. 1090 MHz directional pattern.
B. 1030 MHz omnidirectional pattern.
C. 1090 MHz omnidirectional pattern.
D. 1030 MHz directional pattern.
