Millimeter Wave Injection Locking Synchronization Bandwidth Broadening

The injection-locking technology, characterized by the frequency stabilization, amplification, modulation and etc, has been widely used in the small-signal recovery, frequency synchronization, power synthesis, phase modulation and etc in the microwave, millimeter wave and higher frequency range communication and phased-array systems. Though this kind of circuit has a simple structure and a low cost, the conflict between the reliability of locking and the noise reduction influences the stability and reliability of the system. The thesis aims at finding a proper proposal to solve the difficult issue regarding the reliability of locking and make the system become stable and reliable and in the meantime, simple-structured and low-cost.The paper firstly introduces the various calculation methods of injection-locking bandwidth, compares their merits and demerits and from the perspective of the model analysis illustrates the differences of the bandwidths calculated by these methods. On such a basis, the injection-locking range improvement technology is discussed and the features of various locking range improvement technologies are elaborated. And the new circuit structure for improving the locking range, that is, injection-locked phase-locked loop circuit (ILPLL) is introduced into the millimeter wave circuit. The paper analyzes in detail the characteristics of this circuit in the aspect of locking range improvement and its merits in the aspect of phase noise, and designs the ILPLL circuit in the form of Ka band cavity structure and verifies its characteristics. It can be deduced from the characteristics of ILPLL circuit that injection-locking bandwidth is not only related to the injection-locking bandwidth without feedback loop, but also related to the characteristics of frequency mixing, loop gain and the change of the loop phase. Thus, the needed bandwidth can be obtained by adjusting the loop parameters. And the phase noise characteristics are mainly determined by loop transmission factor. Thus, the better phase noise can be obtained by adjusting the loop wave filtering. Through experimental verification, the locking range of the designed Ka band ILPLL circuit is 2.5 times to 9 times widened and the phase noise, compared to that without feedback loop, is reduced by 4dBc@1KHz and the noise can be reduced by adjusting the loop wave filtering and...