Tham khảo tài liệu 'future aeronautical communications part 10', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Development of a Broadband and Squint-Free Ku-Band Phased Array Antenna System for Airborne Satellite Communications 213 Front-end The projected configuration of the front-end is depicted in Fig. 11a. Here the output signal of 4 AEs will be amplified combined and subsequently downconverted to the L-band 950 3000 MHz . The target values of gain and noise figure for the complete chain have been set to 70 dB and dB respectively. From the front-end design point of view downconversion to the L-band is advantageous to avoid oscillations due to the large amplification. The oscillations can be minimized by means of distributing the gain at the two frequency bands. Due to size constraints it is desirable to use MMICs with a high degree of integration. For this reason the so-called corechips will be used in the design. These are MMIC-building blocks that integrate different functionalities in the same chip. Here the combined functionalities of amplification LNA and phase shifting are desired. The one selected for this design is a corechip that was previously designed for the NATALIA-project Baggen et al. 2010 and manufactured by the foundry OMMIC. It consists of a two-stage LNA 4 bit phase shifter and digital logic. The projected gain and NF of the corechip are 12 dB and dB respectively with an assumption that the coupling loss from the antenna to the chip is less than dB. Fig. 11. a The configuration of the front-end. The corechip consists of an LNA and a 4-bit phase shifter. The NXP chip is used for downconversion and amplification. b Schematic layout of the RF front-end. c Overview of the gain and noise figure of the elements of the front-end chain. The outputs of the four corechips are subsequently combined in a 4 1 combiner followed by an LNA. The down-conversion is performed after combining the 2x2 sub array. The proposed chip for down-conversion here is manufactured by NXP. This chip is a highly integrated circuit that includes an LNA a mixer a .
