Hello i have a series fed antenna array as shown below.
as you can see by the far field all the patches are fed with the same voltage value.
also when i looked at the e-field cut plane i saw the same efield pattern at the feeding of the patch.
I know that that this series fed array acts as a voltage divider from the excitation source.
how can i change a series feeding of this array so i could control the voltage going into the array?
Thanks.
Adding open stubs on the feeding transmission lines between antennas will change the control voltage amplitude.
Changing the length of the transmission lines between antennas will change the phase going into array.
When doing the modifications above, the distance between array antennas should remain unchanged.
Adding stub terminated with a vias can shift frequencies.that depend on your deposition material and substrate's square resistence by different bias voltages .The frequecy shift is bias controlled.You need voltage controlled atenuator between array elements or a single attenuator at the array edge, as you consider.
You can use PIN diode or bias tee for voltage controlled attenuator .