A fully integrated frequency divider with an operation frequency up to 20 GHz is designed in 0.18-m CMOS technology. The frequency divider includes two stages to divide the input signal by a factor of 4. A wide locking range from 18.8 to 23.2 GHz was obtained with a low phase noise of 134 8 dBc/Hz(1-MHz offset) at an output frequency of 4.7 GHz. The first stage is designed by an analog methodology with the varactors to extend the locking range, while the second stage is designed by a digital approach with the RF devices for a high operation frequency. With the advantages of both designs, this frequency divider is operated at the frequency range suitable for LMDS applications.

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In recent years, three types of linacs have been developed for large container inspection for customs application, viz., S-Band 9MeV travelling-wave (TW) linacs, S-Band 6MeV Standing-wave (SW) linacs and XBand 2.5MeV (SW) linacs. In cooperation with Tsinghua Tongfang Co. Ltd, a series of container inspection systems has been produced. Seven sets of large container inspection systems with 9MeV TW linacs have been installed at Tianjin, Dalian, Qingdao, Shanghai, Dapeng, and Nanjing Seaport customs. These systems are called "the fixed type". Based on our development of a compact X-band 9300MHz 2.5MeV SW linac, a novel "mobile type" large container inspection system was completed. Four sets of these systems have been installed in four customs areas. Another container inspection system with a S-Band 6MeV SW linac, installed in a simple shielding shed with cement blocks, is called "the combined type". Four sets of these systems have been equipped in four customs areas.