In this paper, a flexible multi-band linearly frequency modulated (LFM) signal generator based on a dual-polarization binary phase-shift keying (DP-BPSK) modulator is proposed and demonstrated by experiment. Two dual-drive Mach–Zehnder modulators of the DP-BPSK modulator are driven by a local oscillator (LO) signal and an LFM signal, respectively. By appropriately changing the phase difference introduced by a polarization controller, flexible multi-band LFM signals can be obtained after photoelectric conversion. The LO signal is phase modulated to eliminate self-heterodyne, which will affect the quality of the resulting signal.

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From the 20th century, with the development of manufacturing Industry, the concept of division of labor and globalization had become more and more important, manufacturing companies have formed a global production network based on the division of labor in the product value chain. As a well-known company, Apple has built a global supply chain based on this theoretical foundation, as a result, brought Apple huge commercial profits and increase its proportion in the market share. This paper analyzes how Apple flexibly uses the global production network to reduce its production costs and increase profits, as well as the problems that may appears by using this theory. The analysis show that Apple has become a leading company in the electronic technology industry by maximizing the use of global resources and high-precision production processes and techniques, giving it a discourse power of choosing manufacturers. At the same time, Chinese manufacturers are basically in the middle or lower level of Apple's supply chain, which can be most easily abandoned and replaced.

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