A Low Noise Frequency Agile X-Band Source

Microwave Frequency Agile Source for Coherent Radar Applications

“…These included oscillators based on the following resonator types: -5th overtone bulk wave AT or SC-cut crystal in the range 100 to 150 MHz -SAW resonator operating between around 150 MHz and 1 GHz -Bulk wave fundamental resonators between several hundred MHz and 1 GHz It was therefore consi dered essential that the frequency synthesis technique chosen was not dependent on the use of a reference source operating in any particular frequency band. This immediately precluded any scheme (Galini et al [2]) which involved the formation of a basic channel set from harmonics of the reference signal falling within the agility bandwidth, since this could result in the need for frequency division of the reference signal prior to multiplication, with consequent degradation to the phase noise of the multiplied signal. It became clear, then, that the design oould only be made to accommodate a wide range of reference signal frequencies if the frequency multiplication and frequency synthesis functions were arranged to be completely independent, and realised by separate pieces of hardware.…”