LINEAR FM MICROWAVE PHASE-LOCKED LOOP

A description of a phase-locked loop (PLL) is given, which is successfully used in an X-band linear PM inicrowave source with 6 s pules width, 30 MHz bandwidth and 1 ms FM pulse cycle. A phase-locked method is used to obtain the linear FM pulse signal with highly stable starting frequency equal to the stability of the 5 MHz crystal oscillator. The operation of the PLL is under a switching mode. Minimum time delay, rapid ability of acquisition, large synchronous range, good signal to noise ratio, simplicity in consturuction and high reliability with higher power output are the advantages of the PLL used. the characteristic and the approach for the realization of the PLL are described also. This PLL has been used in a remote sensing system and high quality results have been obtained.