RF Design

RF Measurement Library: Capturing Circuit Characterization Setups on the Schematic

2009-07-16T13:00:00Z

Another design approach that Cadence supports that may not be obvious to all users… The process of setting up a circuit simulation has historically been one of setting up all of the simulation control parameters (i.e. which analysis you want to run, what simulation data you want to save, accuracy tolerances, etc.) and then, after the simulation has completed, defining the measurements you want to make (i.e. noise figure, dc supply current, gain, etc.). The expectation here is that the user...(read more)

Periodic Steady-State Analysis for DC-to-DC Converters

2009-06-30T14:30:00Z

In " Spectre RF by any other name ...", a non-RF application for Spectre RF's periodic steady-state analysis was introduced. An example of using periodic steady-state analysis [PSS] to simulate the dynamic performance: THD and SFDR, of a switched-current Digital-to-Analog Converter [DAC] was presented. In this append, we will look at using periodic steady-state analysis for another non-RF application, switching regulator simulation. Switching regulators are the core of switched-mode...(read more)

Join us at the Cadence booth at the International Microwave Symposium

2009-06-08T21:00:00Z

If you listened to Tom's advice on this blog two months ago and registered for the International Microwave Symposium or the RFIC symposium, then you should be at the Boston Convention center now enjoying RFIC talks. Please remember that we are waiting for you at the Cadence booth on the exhibition floor. When you visit the Cadence booth, you will participate in demos and chalk talks about the latest RFIC simulation technologies in the Cadence Virtuoso Custom Design Platform . You will see how...(read more)

Enhanced pnoise Algorithm to Compute Phase-Noise for VCOs with Bandgap Voltage Reference

2009-05-01T13:00:00Z

Accurate phase-noise characterization is critical in the design of RF and microwave communication systems. SpectreRF ’s shooting PSS/Pnoise analysis has been the golden simulator for the phase-noise simulation, and close correlation between the simulation results and silicon measurement was well reported by many research and industrial institutes. As the IC voltage references, such as bandgap reference, are widely used as DC biasing circuitry in deep-submicron low noise VCO design because of...(read more)

2009 RFIC Symposium in Boston - Are You Going?

2009-04-27T13:01:00Z

If you are an RFIC designer then I hope you are planning on attending the 2009 RFIC Symposium and the International Microwave Symposium (IMS) which will be held in Boston, Massachusetts, as the centerpieces of Microwave Week 2009, scheduled from Sunday June 7 through Friday June 12, 2009. The 2009 RFIC Symposium is one of the foremost IEEE technical conferences dedicated to the latest innovations in RFIC development for wireless and wire line communication ICs and emerging applications. Running in...(read more)

Spectre RF By Any Other Name ...

2009-04-22T13:00:00Z

It has been a while since I last appende d , hope you are well! It was a little bit difficult to come up with a subject to write about and then recently I was in a meeting where we were talking about transient noise analysis. A designer was discussing the issue of analyzing the noise of a Pipeline ADC as an example of how they use the transient noise. The conversation started me to wondering whether or not this might be a good application for Spectre RF . After all, Spectre RF PNOISE analysis can...(read more)

Setting VIVA Waveform Color Defaults When Using ADE

2009-04-21T13:00:00Z

I found myself getting a little bit frustrated with some of the default colors that would come up in the VIVA waveform tool while I was plotting from the Analog Design Environment (ADE). After working with Kabir, the Product Engineer for VIVA, I discovered that the colors for the waveform defaults are actually being set by ADE. There are a set of probe layers or Y layers in the Display Resource File that ADE cycles through to match up highlighted nets on the schematic with traces in the waveform...(read more)

Setting Up Harmonic Balance - Part 1

2009-03-18T19:01:00Z

This is the first of a series of Blogs to talk about how to fill out the forms for Harmonic Balance. I will include our suggested settings and some helpful hints. I will add to these over time as new things come up both from us and our customer base. Harmonic Balance works in the frequency domain and is a very efficient way to describe systems operating in steady-state. HB is VERY efficient for systems that have sinusoidal tones. As the tones become more nonlinear, or more "square" in nature...(read more)

Shhhhh.....SpectreRF Tutorials and AppNotes - One of Our Best Kept Secrets!

2009-02-09T11:00:00Z

Did you know that we have hidden a wide variety of SpectreRF Tutorials, Workshops, and Appnotes in your MMSIM hieararchy? In your <MMSIM71>/tools/spectre/examples/SpectreRF_workshop directory there are the following tutorials, appNotes, and workshops: RF Workshop Tutorials The RF Workshop Tutorials show how to simulate typical RF circuits such as LNAs, Mixers, VCOs, and PAs in spectreRF. Note that the database is in cdba (not oa, open access). The RF Workshop HB Tutorials show similar simulations...(read more)

SpectreRF Turbo: Parasitic Reduction

2009-02-02T11:00:00Z

I wanted to share some experiences I had with SpectreRF-Turbo and Parasitic reduction on a recent large benchmark. The things I learned may be helpful to anyone who wants to get the most out of turbo and parasitic reduction. Available in MMSIM7.0.1 and later for RF, turbo accelerates simulation in three ways: 1) by more efficiently evaluating the BSIM3 and BSIM4 devices, 2) the matrix is handled more effeciently and 3) turbo divides the job accross multi-core machines. Parasitic reduction reduces...(read more)

Noise and Jitter Analysis for PLL-Based Frequency Synthethiser Using SpectreRF

2009-01-28T16:37:00Z

Cadence will present SpectreRF Noise aware PLL flow latest enhancements at the DesignCon 2009 conference, based in Santa Clara . In the paper "Noise and Jitter Analysis for PLL-Based Frequency Synthesizer", we fully describe SpectreRF flow and provide a testbench for each PLL building block, such as VCO, PFD/CP, and FD, where their voltage-domain models with noise information are extracted to capture their dominant behaviors. The models are used in the top-level PLL simulation to identify...(read more)

SpectreRF GUI Support for MMSIM 7.1

2009-01-23T14:00:00Z

MMSIM 7.1 has just been released! The following IC release GUIs support the new MMSIM7.1 features: IC5.1.41.500.5.129 (However, USR6 or later is strongly recommended) IC6.1.1 ISR65 IC6.1.3 ISR5 And later subversions. For more information, similar tips, and design topics, please visit sourcelink.cadence.com ....(read more)

MMSIM 7.1 Enhancements Benefit RF Designers!

2009-01-14T20:00:00Z

The 7.1 release of MMSIM is scheduled for mid-January. There are many exciting RF enhancements that will be useful for RF designers. 1. Three new RF analyses using the harmonic balance engine, have been introduced to make the Spectre RF easier to use: HB, HBAC, and HBnoise. HB analysis (hb) provides the periodic steady-state response for typical RF circuits such as LNAs and Mixers. It supports one or more fundamental frequencies (tones). HB analysis combines the Harmonic Balance PSS/QPSS analyses...(read more)

Tip of the Week: Guidelines for getting accurate HB QPSS/QPNoise results

2009-01-09T14:00:00Z

Two of the most important parameters for accuracy are: (1) maxharms (2) oversample maxharms: The accuracy of HB is greatly dependent on the number of harmonics chosen. As a general rule, you should simulate with with maxharms [5 3] and (if memory allows) re-simulate with maxharms [7 3] to see if the answer changes (or not). If the answer does not change, you can be confident about your results. For circuits with dividers, the number of harmonics chosen should equal 5 times the divide ratio. This...(read more)

How to Simulate a Subcircuit (Netlist) With Spectre in ADE

2009-01-07T21:00:00Z

Many users ask, "How do I instantiate a netlist into my schematic and simulate with spectre in ADE?" To instantiate a subcircuit (netlist) in your schematic and simulate with spectre in ADE you need to create a cell with a CDF parameter 'model' which will point to the text subcircuit that you want to use for simulating. Here is the recipe: Create a symbol view for the text subcircuit. Make a copy of this symbol view and call the new view "spectre." Open the base CDF for...(read more)