Hysteresis prediction in autonomous microwave circuits usingcommercial software: application to a Ku-band MMIC VCO

摘要

In this paper, a new method is presented for the simulation ofnautonomous microwave circuits, using commercial software. The method,nespecially suitable for voltage-controlled oscillators (VCO's) andnphase-locked circuits, allows the simulation of the whole solutionncurves as a function of any parameter, enabling the prediction ofnhysteresis phenomena, and thus a realistic determination of thenoperating bands. Immittance diagrams, providing all of the coexistingnoscillating solutions, are traced using commercial software by means ofna new technique. As a parameter varies, a switching-parameterncontinuation method is also used for tracing the possible turning pointsnof the solution curve. The new simulation method has been applied to thendesign of a Ku-band monolithic microwave integrated circuit (MMIC) VCO.nThis circuit, which has been integrated using a commercial monolithicntechnology based on 0.2 Μm gate length pseudomorphic HEMT's,nconstitutes a good example to illustrate the new simulation methodncapabilities. Frequency tuning and output power control are,nrespectively, obtained by varying the varactor and transistor voltagenbias. On-wafer measurements and simulation results showed excellentnagreement