Dual-frequency and dual-polarization antenna array for satellite deployment

Abstract

The development of an aperture coupled microstrip dual-band and dual-polarization 6×6 antenna array system on RO4003C is presented. The antenna array has a multilayer structure that consists of square microstrip elements, placed on each substrate layer to provide dual frequency operation at 14 and 35 GHz. Dual polarization is achieved by using two right-angled microstrip lines and two perpendicular slots to feed the antennas. The microstrip feed line is placed orthogonally from the center of the slot on the ground plane between the substrates. The energy from the microstrip feed line is aperture coupled to each square antenna element through the slot. Two right-angled non-overlapping slots are used on each antenna to enable the two different polarization states. The antenna array has 14 GHz patches on the top substrate layer and 35 GHz patches on the lower substrate layer in order to maintain a similar percentage bandwidth. The microstrip feed lines are located at the bottom of the feed substrate. A symmetric feed structure is followed for the antenna array. The aperture coupling feeding network has the advantage of reduced spurious radiation compared to edge or probe feeds as it utilized highly linearly polarized feed lines and slots, and a large ground plane to prevent backside radiation. The designed antenna array has linear polarization at 45-degrees and 135-degrees at the Ku- and Ka-frequency bands. The array is designed using a hybrid simulation scheme in Keysight Advance Design System (ADS). The ADS Schematic is used for the feed network while the ADS Momentum is used for the antenna elements and the entire array structure simulations. In this way, all aspects of the design (microstrip antenna elements and feed lines) can be optimized independently. This array is suitable for airborne (small remotely piloted), and small-satellite NASA flight programs.