Linear frequency networks with applications to ‘frequency set‐on oscillators’ and ‘self‐adaptive bandpass filters’

A ‘linear frequency network’ is a network system which consists of an arbitrary connection of devices, each of which performs a linear transformation on the instantaneous frequency of a signal. Thus a transfer function may be defined relating the output to input instantaneous frequency. Particular networks are investigated. the first is a basic section, producing a ‘self‐adaptive bandpass filter’ which is then applied to a ‘frequency set‐on oscillator’. Such an oscillator is a multimode oscillator where any mode will be stable when excited by a sample of an RF pulse adjacent to the mode. Cascading these basic sections results in an n th‐degree ‘self‐adaptive bandpass filter’ producing a bandpass characteristic which tracks a carrier frequency. Experimental devices in the 400‐600 MHz band are shown to have excellent agreement with theory, and applications to digital RF memories, ESM receivers and frequency memory loops are discussed.