Multi-Frequency Array Antenna and Communications System

A communications system, comprising:

• a base station;
• and
• a multi-frequency array antenna,
• wherein the base station is coupled to the base station and configured to receive a signal or send the signal using the multi-frequency array antenna, and
• wherein the multi-frequency array antenna comprises:
• a reflective plate;
• and
• at least two microstrip antennas operating at different operating frequency bands, wherein each of the at least two microstrip antennas comprises a respective feed network and a respective radiating element set, wherein the at least two microstrip antennas comprise a first microstrip antenna and a second microstrip antenna, wherein a first radiating element set of the first microstrip antenna comprises a plurality of radiating elements arranged in an array, wherein a second radiating element set of the second microstrip antenna comprises at least one radiating element, wherein the first radiating element set and the second radiating element set are located on a same side of the reflective plate, and wherein there is an overlapping region between a graph constituted on the reflective plate by the plurality of radiating elements in the first radiating element set and a graph constituted on the reflective plate by the at least one radiating element in the second radiating element set.