Meaning
Antenna configurations where radiating elements are connected in a sequential chain minimize the space required for feed networks on a circuit board. A series fed patch array uses a single transmission line to excite multiple patches in a row. This design reduces the complexity of the routing compared to parallel feed structures.
The definition applies to the layout of the radiating elements and the connecting microstrip lines.
Feeding Mechanism
Power travels from one patch to the next through narrow impedance-matching sections. In a series fed patch array, the dimensions of these connecting lines control the amplitude and phase of each element.
Linear Distribution
Proper spacing between elements is necessary to ensure the radiation from each patch adds constructively. A series fed patch array often produces a narrow beam in the dimension of the array. By adjusting the length of the interconnects, engineers can steer the beam or reduce the side lobes.
This arrangement is effective for vertical scanning in automotive sensors.
Phase Shift
Frequency changes cause the phase between the patches to shift, leading to beam squint. Because the delay is cumulative along the chain, a series fed patch array is sensitive to the operating bandwidth.
