SmartSpice RF Harmonic Balance Based RF Simulator. Advanced RF Circuit Simulation

SmartSpice RF Harmonic Balance Based RF Simulator Advanced RF Circuit Simulation

SmartSpice RF Overview Uses harmonic balance approach to solve system equations in frequency domain Well suited for RF and Microwave Circuits as they are naturally handled in frequency domain Simulation run-time is relatively insensitive to the numerical value of the excitation frequency Frequency dependent distributed elements such as transmission lines are handled without any difficulty - 2 -

SmartSpice RF Inputs/Outputs - 3 -

Silvaco RF Design Flow with RF PDK - 4 -

SmartSpice RF Analyses SmartSpice RF is an option feature added to SmartSpice, and it is represented by 12 analyses:.harmonic Periodic Steady State Analysis.HAC Periodic Steady State AC Analysis.HTF Periodic Steady State Transfer Function Analysis.HNET Periodic Steady State NET Analysis.HNOISE Periodic Steady State Noise Analysis.HOSCIL Periodic Steady State Analysis for autonomous circuits oscillators - 5 -

SmartSpice RF Analyses (con t).spectral Quasi- Periodic Steady State Analysis.SPAC Quasi- Periodic Steady State AC Analysis.SPTF Quasi- Periodic Steady State Transfer Function Analysis.SPNET Quasi- Periodic Steady State NET Analysis.SPNOISE Quasi- Periodic Steady State Noise Analysis.ENV Envelope Following Analysis - 6 -

.HARMONIC (Periodic Steady State Analysis) Harmonic Balance Methods Frequency-domain non-linear simulation techniques Optimal convergence for simulation Provides a complete set of interactive control parameters Spectral-Newton, Continuation, and GMRES solvers Parameter Sweep Power or Frequency Sweep Computes P1dB, IP3 Monte-Carlo Analysis Embedded in each SmartSpice RF analysis Unique ability for statistical distribution of gain, power, etc. - 7 -

SmartSpice RF Small Signal Analyses.HTF Periodic Steady State Transfer Function Analysis Transfer functions from any input to a single output Any input from any image Applications: Conversion gain, image and sideband rejection, power supply rejection.hac Periodic Steady State AC Analysis Transfer functions from a single input to any output Any output at any sideband Applications: Conversion gain, intermodulation distortion.hnoise Periodic Steady State Noise Analysis Applications: Noise figure of mixers, phase noise of oscillators, noise of SC-filters & sample-and-holds - 8 -

SmartSpice RF Small Signal Analyses.HNET Periodic Steady State NET Analysis Computes s-parameters for 2-port circuits that exhibit frequency translation 2-port linear noise option Capability to plot Rectangular Chart, Smith Chart, Noise/Gain/Stability circles. Useful for impedance matching, tuning, and optimization - 9 -

.HTF (Periodic Steady State Transfer Function Analysis) Single output, multiple input frequencies Conversion gain Image and sideband rejection Supply rejection LO feed-through Input Output LO Sideband index is relative to output frequency - 10 -

.HAC (Periodic Steady State AC Analysis) Single input, multiple output frequencies Frequency response Conversion efficiency Intermodulation distortion Input Output LO Sideband index is relative to input frequency. - 11 -

.HNOISE (Periodic Steady State Noise Analysis) Noise is replicated and translated by LO Mixers and Samplers Oscillators Switched Capacitor Filters Noise Output LO - 12 -

.SPECTRAL (Quasi-Periodic Steady State Analysis).SPECTRAL Analysis can simulate the circuit with multi-tone excitations, all of them treated as large signals Time domain waveform and frequency domain waveform are directly computed. Time domain output is useful to check distortions and clipping Output includes intermodulation distortion caused by frequency translation of harmonics from all input signals - 13 -

Highlights on SmartSpice RF examples Lab 1: RF Mixer Design and Analysis 1 db Compression Point 3rd Order Intercept Point Conversion Gain Response Noise Figure Lab 2: RF LNA Design and Analysis S-Parameter Extraction Gain and Stability Circles Lab 3: RF VCO Design and Analysis Transient Simulation Frequency of Oscillation Extraction Phase Noise Spectrum - 14 -

Lab1: Mixer Simulation- 1 db Compression Point.HARMONIC used to compute P1dB LO 1G RF 920MHz Prf -20dBm to 0dBm Prf Power level of RF Source. HARMONIC 1 large tone in LO+ 1 large tone in RF - 15 -

Lab1: Mixer Simulation- 1 db Compression point 1dB Compression point is - 6 dbm. - 16 -

Lab1: Mixer Simulation- 3rd Order Intercept Point.HAC used to compute IP3 LO: 1G RF1: 920MHz, RF2: 921MHz prf: -24dBm to -2dBm prf: Power Level of RF Source HAC: LO plus 1 large tone (RF1) + 1 small tone (RF2) 1st order harmonic: 79MHz 3rd order harmonic: 81MHz - 17 -

Lab1: Mixer Simulation- 3rd Order Intercept Point 3 rd Order Intercept point is 12.3 dbm. - 18 -

Lab1: Mixer Simulation- Conversion Gain.HTF used to compute Conversion Gain LO: 1G RF: 920MHz Terminate prf with 50 ohm. SB(-1,1) is mixing product @ PIF - 19 -

Lab1: Mixer Simulation- Conversion Gain The Conversion Gain is around 18.5 db @ 80 MHz. - 20 -

Lab1: Mixer Simulation- Noise Figure.HNOISE used to compute Noise Figure LO: 1G RF: 920MHz Terminate prf with 50 ohm. refsb= -1is the single sideband noise figure @ PIF - 21 -

Lab1: Mixer Simulation- Noise Figure The Noise Figure is around 13 db @ 80 MHz. - 22 -

Lab2: LNA Simulation- S Parameter.HNET used to compute S Parameter RF: 900MHz Frequency sweep from 100MHz to 1.2GHz - 23 -

Lab2: LNA Simulation- S Parameter S11, S22, and S21 in Cartesian Chart. S11in Smith Chart. - 24 -

Lab2: LNA Simulation- Gain and Stability Circles Specify LOAD_STAB_CIRCLES, SOURCE_STAB_CIRCLES, GAIN_CIRCLES, and POWER_GAIN_CIRCLES in.hnet to compute these parameters RF: 900MHz Frequency sweep from 800MHz to 1.0GHz - 25 -

Lab3: VCO Simulation- Transient Analysis.TRAN used to compute transient behavior and determine oscillation frequency - 26 -

Lab3: VCO Simulation- Transient Analysis Time domain signal is transformed into frequency domain by FFT. Oscillation frequency is around 1.86GHz. - 27 -

Lab3: VCO Simulation- Phase Noise Analysis.HNOISE used to compute phase noise behavior Frequency sweep for single sideband from 1Hz to 10MHz - 28 -

Lab3: VCO Simulation- Phase Noise Analysis Phase Noise is around -54 dbc/hz @ 1KHz, and 84 dbc/hz @ 1MHz - 29 -

Conclusion SmartSpice RF is applicable to periodically driven circuits Exhibits frequency conversion such as mixers, amplifiers, oscillators, filters, and detectors Easy convergence on nonlinear circuits Simulation run time is insensitive to the excitation frequencies Integrated with Silvaco front-to-back MS/RF design flow - 30 -