Referring to the
laptop radar in Figure 1, the center-to-center spacing of two
vertically polarized coffee cans is typically about 20 cm,
and the measured transmit/receive mutual coupling (S21) at
2.4 GHz is -39 dB. Thus for this simple design with two
circular waveguide antennas for transmit and receive, students
are made aware of a number of important topics in antenna
design including waveguides, probes, polarization, reflection
coefficient, gain, radiation patterns, transmit power density,
receive power, antenna arrays, and mutual coupling.