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248 Threads found on Spectrerf
I have a problem in convergence of a circuit consists of an oscillator locked to the frequency of voltage source. I use tstab with enough values with no progress. My accuracy is "conservative". The waveform (of both steady stare and tstab) comes at the output , but non-convergence warning comes too! Have a look at the picture attached. [ATTA
I use spectrerf. the results that I showed is the result of transient analysis. what do you mean by steady state analysis please?Autonomous Harmonic-Balance or Autonomous Shooting-Newton. Waveforms is contradictory to descriptions you wrote in #6.
Hi, Going to use Cadence spectrerf to check DCDC buck converter AC characteristic (gain margin, phase margin, crossover frequency). Any reference? or Tutorial to use spectrerf for DCDC? I think I have to use PAC (periodic AC) analysis in spectrerf analysis setting but I have no idea how to create DCDC testbench and also set analysis (...)
Hi, I am using HB analysis in spectrerf to design a kind of mixer. To do effective HB analysis, I use Transient-Aided Option>Run transient>Decide Automatically. However, I can't find 'Decide Automatically' option as below. Please, let me know what's wrong. 114556
Hi You can find design workshop for mixer at spectrerf manual in MMSIM folder or just by clicking on "help" button in cadence virtuoso. In this workshop you'll find information about simulation key parameters of mixer/lna/vco.
... I get a list of input sidebands and output sidebands. ... What are input sidebands? I think these are just back-computed input frequencies due to the output sidebands. At least I found a hint about this in the spectrerf Simulation Option User Guide: 113190
Hi, I use tsmc18 RF model to model my NMOS. The RF model of the NMOS itself is a sub-circuit. When I run pss with spectrerf, it showed warning for the NMOS: "M0: Missing bulk-source diode would be forward biased", but I actually tied bulk and source together and they are tied to ground. I run transient and probe the voltage of bulk and sou
Hello, If I do SP analysis in spectrerf for a frequency range, how can I get its equivalent series R,L,C and parallel R,L,C? Is there any suggested fundamental book I can refer? Many thanks.:razz:
You should do a PSS analysis first to determine the frequency of oscillation then PNOISE to get Phase Noise at offset frequencies. But you should refer to spectrerf User Guide for more explains the PSS+PNOISE analysis for oscillators in more detailed.
in Cadence spectrerf, is there coupler model? or behavior model? how about bi-directional coupler model? if there does, please tell me where to find that! thanks!
dear all i need your help,here is my question:i want to use PXF analysis of spectrerf simulator to evaluate the power noise effect on the phase noise of VCO output.but i cannot get the waveform. my PSS setting is like this: .beat freq=400M //VCO output 426M .number of harmonics =10 .accuracy default: moderate .tstab=200n .
Hi, I am trying to simulate RF power amplifier using Cadence. There is a guide file entitled "spectrerf Workshop Power Amplifier Design Using spectrerf MMSIM61". I want to follow the tutorial but the problem is that there is only block diagrams not detailed schematic. Could anyone tell me where can I find the detailed schematic for RF power ampli
How to generate a ramp voltage in Cadence spectrerf (or AMS)? I am designing a compartor and need to give a ramp voltage at one of its inputs, the other input being a dc voltage. Can anyone suggest me ideas to generate a ramp voltage. Thank you.
Not observing the suggestions for PSS analysis of oscillators in the spectrerf manual?
Greetings everyone, I'm trying to simulate a power amplifier and find the load-pull contours. I've done the state setup and the design set up as the spectrerf manual says. The thing is, spectre can't seem to understand the portAdapter symbol. When trying to simulate the design, I get an error as shown in the picture below. The parameters that ar
Greetings Reader, I am simulating an amplifier (A simple one) The amp is merely a differential pair with a tail current source and resistive load. Differential Input Differential output. I placed 2 ports at the Gates of the Pair - each of them having first and second sinusoid amplitude set to pin in dBm and swept pin in a swept PSS analysis
There are 3 frequencies in my circuit: frf = 1955MHz, LO1 = 1960MHz, and LO2 = 1950MHz. I'm setting up a 2-tone HB analysis: hb hb oversample = fundfreqs= maxharms = When the simulation runs, it keeps telling me: ERROR (SPCRTRF-15268): The source V63 couldn't find matched freq. Please make sure the fundfreqs
I have tried a simple circuit to check the harmonic. However, the harmonic is observed for the input port. I have no idea for explain this. Very appreciate for you any help. The following is the main flow in my work, (1) Schematic: Only one capacitor 10 pf, Port 1 is set sin source with 50 ohms res, freq=900MHz,Power=30 dBm, Port 2 is set as DC
What is the best option to create user-defined models for use in circuit design using Cadence Analog Design Environment/spectrerf?
I have a /4 divider ahead of the mixer. I wanna know how to set the simulation station in spectrerf environment. Use QPSS or PSS? What's the value of fundamental frequency? Best thanks!
You can see this material:Simulating Switched-Capacitor Filters with spectrerf~I designed one 4th order switched capacitor biquad filter in UMC 180 nm technology using cadence software (version 5.10.41).This circuit is operating on a two phase non overlapping clock generator (i/p frequency = 1 kHz). To simulate this circui
Which one is the best choice to use for RF Ckt design including non-linear transistors?
I understand that the spectrerf simulator does switched-capacitor simulation which includes noise calculations, and that should do the CDS simulation you need. Do you have that? Hi Crutschow, I do not have Spectre RF. i am using Spectre with IC 6. It has option to do Transient Noise Analysis. But, It can only do
I hava a trouble:sad: I want to do noise analysis of the SC circuits. I can use Spectre, but I cannot use spectrerf since we don't have the license. Does someone have any idea? I can use HspiceRF. Can HspiceRF simulate noise analysis of SC circuits? If someone knows, Please tell me!
I am trying to simulate a current-mode mixer which simply consists of quad switching pairs. At first I used isource at the input. But when I want simulate the mixer's distortion performances, e.g. IIP2, IIP3.. with spectrerf, I need to replace isource with power based PORTs. The problem is my circuit input is driven by current, and I need to fill i
69589 The simulation results are shown in the figure. BSIM3v3 model is used in this simulation. The simulator is spectrerf. The MOS operation points in condition A & B are identical. Assuming i = gm*vgs + K2gm*vgs^2 + K3gm*vgs^3 + gds*vds + K2gds*vds^2 + K3gd*vds^3. The first problem is that I think IIP2A should be
Hello guys, Regarding phase noise simulation of oscillators: which tool (spectrerf - PSS/PNOISE analysis or GoldenGate) provides the most accurate results? Is there any material comparing the performance of both tools? Mathematically: do they compute the phase noise in a different way? Thank you very much, Best regards,
Hello everyone, I encounter some boring warnings and errors listed as follows during PSS simulation in Cadence spectrerf. Warning from spectre at time = 475.28 fs during periodic steady state analysis `sweeppss-014_pss', during Sweep analysis `sweeppss'. M0: Vgd has exceeded the oxide breakdown voltage of `vbox' = 4.08 V. M1
You could reference the spectrerf manual located in your cadence installation directory under doc folder.There you will find good explanations and the answers to the above issues you posed. Look into it and if you feel that you need more clarifications come back and ask for more help.
Hi there! Does anybody know how to access umc optimum capacitor/inductor finder tool, available for spectrerf, from ocean scripts? Thanks in advance
So,the best reference for your concern is spectrerf.pdf and spectrerftheory.pdf documents located at your cadence installation directory under subfolder named doc. Additionally always consult your pdk manuals.
now how to calculate the gain and bandwidth of common mode feedback loop.....????? Break the loop at some point with an iprobe component from analogLib and run stb analysis.That's all! no of harmonics=1 (don't know how to set this Can Anybody tell me??) Dig into spectrerf manual (it is located in your cadence instal
See the Virtuoso? spectrerf Simulation Option User Guide, pp. 1124 ff. (from Product Version 5.1.41 July 2005 / November 2005).
Hello, I am trying to run a PSS analysis with spectrerf for a Ring Oscillator and at the end of simulation, while transient simulation is completed succesfull, I get the following message from PSS: " Even after adjusting the tstab value, PSS still failed to converge". Does anybody suggest a solution for this problem, Thnx
Anyone had any success (in silicon) with the any of the various GOC switched cap CDS integrators? I am designing a biquad HP filter using the nagaraj style GOC integrators and the offset correction is not too impressive in simulation (I'm using Spectre for tran sims and spectrerf for pac & pnoise). For example a standard SC integrator where b
Use S-parameter of Touchstone format. The Designer's Guide Community Forum - conversion of .s8p into spectrerf netlist
In the SP analysis of spectrerf, it also calculate the Z11, Z22, etc.. Is that the Zin or Zout of the two ports circuit? Z parameters are different from Zin/Zout. Z parameters are defined with i=0 (open circuit) at the other ports. Zin/Zout are usually measured with proper termination at the other ports.
Hello, I´d like to do a cosimulation between cadence and simulink to simulate my low-level design within my simulink model. I did all the settings (as described in the Co-simulation with spectrerf Matlab/Simulink Tutorial), so all paths have been set correctly. And the spectrerf engine is found in my simulink model file. In the ADE L envir
Hello all, I know this is a repeated question without a definite answer, but I have to ask this again. Have you ever seen a example of PLL design flow with cadence or other cad tools? It does not matter whether it's based on Cadence spectrerf or Synopsys HspiceRF. I know Cadence has "Noise Aware PLL Design Flow", but the design database
Hi Guys I need spectrerf software to model PLL and predict its phase noise. Guide me from where I can download it. Thanks
I have the following question: If I do iip3 simulation for an LNA and after choosing the output, the iip3 is -3dBm for example. If I choose the net of the input as the output for iip3 calculation, it will be -3dBm(ideally it should be infinity), Why does this happen ? I use PSS followed by PAC for simulation. thanks in advance, Moham
Hello, I encoutered a problem when simulating a circuit that contains a freuency divider using the Envelop Analysis in spectrerf. I have taken the following step: 1. The "oversample factor" is set to be 2 because the divider halven the input frequency 2. The "freqdivide" in the option form was set to be 2 correspondingly. 3. The other settings a
ngspice will not do the periodic steady state/harmonic balance analysis that spectrerf provides. Sorry.
Hello, everyone I have design a up-conversion mixer, IF=400MHz,LO=2600MHz and RF=2200MHz. I want to use PSS+PAC to simulation mixer IIP3 follow "spectrerf User Guide", and find a question when set PAC simulation"Array of indices" Because I set fundamental tone of 200MHz, Lo at 2.6GHz, and two IF tones at 400MHz and
hi Also I have the above problem. Why there is not any newer version of "simulating switched-capacitor filters with spectrerf" document for spectrerf2008? In the above doc the netlist defines only the period and maxacfreq; while in specreRF there are so more parameters required, for example "Fundamental tones" and beat frequency simultaneusly. A
I read that for doing a pss analysis in spectrerf except clock other signals (including input) should be zero. now if I want to do at first a PSS analysis and then based on its data do a PAC analysis for a circuit, what is the detailed procedure? please say each step in detail for spectrerf environment. For the above procedure is there any differe
As I read in spectrerf (product version 5 2003) there isn't fundamental tones block for PSS analysis and only one fundamental frequency is needed. But in spectrerf product version 6.2 (2007) there is a block with "fundamental tones" title and it is for PSS. How is it possible to use more than one tones for PSS? Regards
I made a 2.4G LNA with pre-layout simulation NF of 1.9dB using spectrerf, but it increased to nearly 4dB when did post-layout simulation. I have optimized the layout several times, and NF still was nearly 3.9dB, what is the problem most likely? top thick metal was used to pass RF single, and the RF path was as short as possible. all models u
hi Is there any windows version of spectrerf? where can I find the manual (pdf) file of spectrerf while I have not the software itself? I want to be familar with its using. Regards
Hi ,all. when I simulate my PFD/CP current noise with spectrerf, I found there is some wrong that the curve of current noise go up with frequency. so, anyone can help me? Thanks. my simulation setup like :