VARACTOR-LOADED LADDER LINES FOR TRAVELLING-WAVE PARAMETRIC AMPLIFIERS AND VOLTAGE-TUNABLE MICROWAVE CIRCUITS.
MICHIGAN UNIV ANN ARBOR ELECTRON PHYSICS LAB
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The purpose of the study is to investigate the properties of a varactor-loaded ladder-line structure for application as a traveling-wave parametric amplifier and voltage-tunable filter, delay line and phase shifter. In order to account for losses, and design appropriate coupling sections, an equivalent-circuit method is developed utilizing the Richards frequency transformation to obtain the properties of coupled ladder-line structures. It is shown that the pass band of the structure, time delay, and phase shift per section can be tuned over a considerable range with proper circuit design. An experimental varactor-loaded ladder-line structure is discussed for X-band. Eight sections have been used to obtain a gain of more than 15 db over an instantaneous bandwidth of 300 MHz. The frequency band can be tuned over 1 GHz by varying the diode capacitance and the pump frequency. Author
- Electrical and Electronic Equipment