Phased. FreeSpace - Multipath issue

We have used phased.FreeSpace for our channel. We could see the presence of two taps in the channel. Could you clarify this?

The following is the code.

fs = 8000; fop = 3e9;

channel = phased.FreeSpace('SampleRate',fs,'OperatingFrequency',fop,'TwoWayPropagation',false);

pos1 = [1000;0;0];

pos2 = [300;200;50];

vel1 = [0;0;0];

vel2 = [0;0;0];

y = channel([1;zeros(1000,1)],pos1,pos2,vel1,vel2);

figure;

z=abs(y);

plot(z(1:10));