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Saab Ericsson Space has developed an L-band Patch Excited Cup (PEC) that is especially suitable as an array element for mobile communication service systems. The design is focused on a robust but lightweight antenna solution with as few separate parts as possible to ensure good PIMP (Passive Inter-Modulation Products) performance. The design also ensures low axial ratio (LHCP and RHCP) over a wide reflector subtended angle. The wide frequency bandwidth, in addition, makes it an excellent choice for modern communication systems using common receive and transmit antennas. This paper gives the description of the design and also typical measured data. DescriptionThe antenna element consists of a stacked disk antenna mounted within a conical cup with circular cross section of approximately U 4 height as shown in Figure 1. The cup is flared to give low cross polarisation levels at wide angles (Le f42'). In addition, a special pending patent design is used inside the cup to further decrease the axial ratio in circular polarisation (CP) mode. A typical CP radiation pattern is shown in Figure 2. The radiation pattern is measured including coupling in a 5-element Breadboard array. Each PEC is fed by two orthogonally placed probes which excite the lower disk electromagnetically through a metallic tube. This tube acts as a capacitance thus compensating for the probe inductance. The two feed ports provide dual linear or dual circular polarisation upon telecommand via an external beam forming matrix (not part of the antenna). The element is designed to achieve low axial ratio assuming equal amplitude and 90" port excitation. The typical axial ratio as an average over all $-cuts has been optimized to be less than 2.0 dB over f42" as shown in Figure 3. 0-7803-2009-3/94/$4.00 0 1994 IEEE. 902