Oscillator and Phase Noise Analysis Options Reference

Option

Default Value

Description

freq_abstol

10

Relative tolerance for oscillation frequency

harmonic_number

None

Oscillator harmonic to compute phase noise for (Phase noise analysis only)

initial_guess

transient

Select method for initial guess at probe frequency

dc = use FREQ parameter on the oscillator probe.

freq_sweep = run frequency sweep

transient = run transient analysis

initial_guess.freq_sweep.method

linear

Linear or nonlinear solution type for frequency sweep initial guess

initial_guess.freq_sweep.num_steps

50

Number of steps for frequency sweep

initial_guess.freq_sweep.start

1e9 Hz

Start frequency for frequency sweep

initial_guess.freq_sweep.stop

5e9 Hz

End frequency for frequency sweep

initial_guess.transient.num_cycles

Calculated

Number of periods for transient initial guess (like stop time)

initial_guess.transient.output_start

0

Initial time during transient analysis that is ignored by initial guess

initial_guess.transient.tmax

Calculated

Maximum step size for transient analysis

initial_guess.transient.tstep

Calculated

Maximum step size for transient analysis

initial_guess.transient.tstop

Calculated

Stop time for transient analysis initial guess

iprobe_abstol

1e-11

abstol for probe current

maxk

None

Maximum number of harmonics at each frequency (Phase noise analysis only)

noise_output

None

Node or branch to compute the phase noise on (Phase noise analysis only)

nonlinear_method

newton

Newton-Raphson iteration strategy

newton = standard Newton-Raphson

damped_newton = use ΔV damping

descent = follow slope of derivative

nonlinear_method.descent.num_iterations

100

Maximum number of steps in descent initial guess.

Mainly for internal use.

nonlinear_method.descent.param.f_tolerance

1e-4

Function reltol in descent

Mainly for internal use.

nonlinear_method.descent.param.max_step

0.01

Maximum normalized step size in descent

Mainly for internal use.

nonlinear_method.descent.param.step

1e-4

Normalized step size in descent

Mainly for internal use.

nonlinear_method.descent.param.tolerance

0.01

reltol in descent

Mainly for internal use.

nonlinear_method.descent.param.

1e-4

Function reltol in descent

Mainly for internal use.

nonlinear_method.newton.barrier

2

Power of the barrier that prevents probe from zero voltage.

Mainly for internal use.

phase_noise.method

stochastic

Select stochastic or time_varying method for phase noise computation

reltol

1e-4

Relative voltage tolerance for NR iterations

result_as_initial_guess

false

When set to true, result from previous sweep step is used as the initial guess for the current sweep

tones

None

Approximate oscillator frequency

vprobe_abstol

1e-5

abstol for voltage probe