A differential phase encoding microwave signal generation method and device

Abstract

The invention discloses a generation method and device of a microwave signal with a differential phase code, and belongs to the technical field of communication, radar and microwave photonics. The device comprises a laser, a first electro-optical modulator, a second electro-optical modulator, a cascaded Mach-Zehnder interferometer, a balanced photoelectric detector, a microwave signal source and a code signal generator. The method specifically comprises the following steps: performing suppressed carrier modulation on direct current light by using the first electro-optical modulator to obtain two subcarriers; modulating the phase of the code signal on the abovementioned two subcarriers by using the second electro-optical modulator; separating the two subcarriers by using the cascaded Mach-Zehnder interferometer and introducing a proper time delay difference; performing photoelectric detection on two paths of light signals output by the cascaded Mach-Zehnder interferometer by using the balanced photoelectric detector to obtain the microwave signal with the differential phase code. The method and the device have the main advantage that the microwave signal with the differential phase code can be generated, and has the advantages of high carrier frequency, high bandwidth and no low-frequency noise interference.

Description

technical field [0001] The present invention relates to a differential phase encoding microwave signal generation method and device, in particular to a differential phase encoding microwave signal generation method and device based on microwave photon technology, belonging to the fields of communication, radar and microwave photonics. Background technique [0002] Phase encoding or differential phase encoding is a commonly used modulation format in microwave communication systems, and it is also one of the key technologies for realizing pulse compression in radar systems to improve range resolution. In particular, using a differential phase encoding format can significantly improve the reliability of a microwave communication system. As the carrier frequency and bandwidth of phase-encoded signals required by communication and radar systems continue to increase, how to generate high-frequency, large-bandwidth phase-encoded signals has become an urgent problem for communicatio...

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Problems solved by technology

In recent years, researchers have proposed many methods for generating phase-encoded signals based on microwave photonic technology, but these methods usually have the following problems: First, since the photodetector follows the square-law detection when realizing photoelectric conversion, the obtained phase There are many low-frequency components in the encoded signal, and filters must be used to remove the low-frequency components before the signal is transmitted, which increases the complexity of the system; second, the carrier frequency of the obtained phase-encoded signal is the same as the frequency of the microwave signal source of the drive system , so to generate a high-frequency phase-encoded signal must use a high-frequency microwave signal source, which increases the system cost; third, if a differential phase-encoded microwave signal needs to be generated, the differential encoding of the signal must first be completed in the electrical domain. Then it is used as the input of the microwave photonic system, instead of using the original coded signal as the input to directly generate the differential phase coded microwave signal

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