Tunable microwave oscillators employing narrowband MSSW delay lines

Attention is given to the results of an experimental study of microwave tunable oscillators using magnetostatic wave (MSW) delay lines whose narrowband characteristics were obtained by means of lifted transducers with magnetostatic surface waves. A bandwidth of 10 MHz resulted, with an insertion loss of less than 20 dB. While a mode-hopping problem encountered in earlier studies on such devices was overcome, frequency jumping occurred whenever the electrical length of the circuit external to the delay line changed by 360 deg. It is concluded that if the electrical length of the external circuit is sufficiently reduced, ideally to zero, single-mode operation over an octave bandwidth or more is possible.