Wilkinson power divider with phased array antennas
I understand how an equal split Wilkinson power divider works in supplying equal phase and amplitude of signals to the antenna elements of a phased array.
But what happens when the phased array is used as a receiver? The received signals are phase shifted and then combined. So the power combiner has phase shifted inputs and how then does the power combiner work?
Some may say that the phase shifted inputs result in reflections which is taken care of the resistor providing isolation between the output ports. But what when my design is without a resistor between the output ports?
if a freespace source is, say , 20 degrees off to the left of boresight. Then the phase array recieve will not see it unless you ADD a phase shift to all of the elements, so that the total phase shift is 0 degrees. There need to be phase shifters at each antenna element, each with its own individual phase setting
Yes.. there is a phase shifter at each antenna element...
The transmitter and the receiver are in line. The receiver is a phased array. So after picking up the signals, phase shifts are introduced and then combined.
... to compensate the phase shift caused by different path length at non-zero incident angles to the antenna array. Total phase shift is then zero again in the array target direction, or non-zero in other directions.
Then it's not a Wilkinson power divider...