K-band CMOS phase shifter with low insertion-loss variation

On the design of CMOS phase shifters with small insertion‐loss variation for phased arrays and its validation at 24 GHz

“…Planar antennas have been widely studied and proposed for several modern wireless applications due to their low profile, ease of integration to communication systems, and high design flexibility. Such characteristics, along with a circular polarization, make them excellent candidates for integration on small satellites, particularly for CubeSat platforms, compared to wire antennas [1][2][3][4][5][6][7], linear wire-arrays [6], or helical antennas [6,7], where a large number of elements are required, or expandable structures which are bulky and prone to mechanical errors are utilized. Moreover, the use of the 2.4 GHz band for small satellite applications allows the antenna structures to present low dimensions and higher gain values when compared with the VHF band, or even the lower part of the UHF region, making the mentioned frequency allocation (2.4 GHz) one of the favorite choices released by the International Telecommunication Union ITU for the amateur satellite systems [4].…”

“…Phase shifters having low insertion losses also make it possible to design phased arrays without additional attenuators/variable gain amplifiers, which have fine attenuation/gain steps to compensate for the fluctuating insertion loss caused by the phase shifters. Some techniques have been proposed to reduce the insertion‐loss variation of phase shifters . These designs, however, have relatively large size due to the use of hybrid couplers and hence are not attractive for radio frequency integrated circuit (RFIC) due to expensive silicon real estate.…”