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Calculators
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As engineers, we appreciate useful tools that help us get our job done in an efficient manner. With that in mind, we at Custom MMIC Design Services have created a series of free, web-based calculator tools. There is no need to log in or register. Simply use them and get your job done faster. Over the upcoming months, we plan to add more of these tools, so please check back often.
LEGAL DISCLAIMER: These calculators are provided free-of-charge for informational purposes only. While these tools have been checked for accuracy, there is always the chance we made a small mistake somewhere, so please let us know if something doesn’t look right. Also, the thermal calculator is especially meant as a back-of-the-envelope tool and should not be used for critical thermal applications. Instead, the thermal calculator tool is best used to identify a potential thermal problem package mounted to a printed circuit board. If you notice that the calculated temperature is very close to the specified limit of your component, we encourage you to verify your results with a finite-element thermal analysis tool such as ANSYS. Alternatively, we can assist you in any critical thermal applications. Just contact us and we’d be happy to quote your particular application.
Finally, please do not hesitate to contact us with questions or comments regarding these calculators, especially if there’s one you’d like to see in the future.
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Attenuator Thermal Image Rejection Cascade Analysis
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Attenuator Calculator
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The following tool will calculate the resistor values for a PI, TEE, and BRIDGED-TEE attenuators. Simply enter your required attenuation level and system impedance and let the calculator figure out the resistor values. Easy as pi. Or tee. Or bridged tee, whichever you prefer…
Attentuator Calculator
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Thermal Calculator
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When it comes to thermal analysis, one of the biggest mistakes engineers make is to assume the temperature at the bottom of their package is simply the ambient or “base plate” temperature. But as we all know, packages get mounted onto PC boards, and those PC boards have thermal properties all their own. So the obvious question thus becomes, “What is the actual temperature at the bottom of my package?"
That’s where this calculator comes in. With this tool, you can now estimate the temperature at the bottom of your package based upon the construction of the PCB. You set the package type, the power dissipated inside your package, the PCB board material, the via construction, and the base plate temperature (typically 85 ºC). The calculator then determines the temperature rise through the PCB to the bottom of the package, under the following assumptions: the PCB is plated with 1 oz. copper (1.4 mils thick), the package is attached to the PCB with solder (2 mils thick), and the base plate is an ideal heat sink.
However, we cannot state this enough: This tool is best used to get a ball-park estimate of the temperature rise from the base of the PCB to the bottom of your package. There are quite a number of variables to play with here so take your time. Again, if you find that the temperature at the bottom of your package is too high, we encourage you to verify the results with a finite element thermal analysis program such as ANSYS. If you need help with such analysis, please do not hesitate to contact us. Let us use our expertise to understand and solve your thermal problems. Cooler heads will prevail!
Thermal Calculator
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Image Rejection Calculator
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When it comes to image rejection, one question more than any other dominates the conversation: “How can I get more?“ As we all know, image rejection is controlled by the phase and amplitude error within the system. However, we don’t always know which of the two errors is exerting more influence on the performance. Our image rejection calculator helps solve this dilemma. The tool is essentially a plot of the contours of constant image rejection as a function of phase and amplitude error. We display only positive quantities on the graph since image rejection is symmetric about these errors. But then comes the fun part. We’ve added two fields where you can enter your specific amplitude and phase error. Once you hit “calculate“, we determine the associated image rejection and add this value to the graph. We then label your point as “You are here,“ because it’s always good to know exactly where you are. And from this point, you can easily see which error you must reduce in order to get the image rejection right where you need it to be.
Image Rejection Calculator
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Cascade Analysis
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When it comes to microwave systems, we engineers usually rely on cascaded analysis to tell us how the individual components will interact with one another. In fact, I’d guess that nearly every microwave engineer has written his or her own cascade analysis tool at some point, or used a freebie such as Agilent’s AppCad or the one from the Microwaves101 website. But all of these calculators have one built-in problem: all stages must be specified with either input or output power parameters, and there is no method to change the reference point from one stage to the next. Unfortunately, component providers are not as consistent when it comes to providing these specifications, and that can prove quite frustrating. Most active components such as amplifiers, for example, are specified in terms of output power and output IP3, but passive components such as mixers and attenuators are often specified by their input values. This mish-mash of specifications used to mean that you, the microwave system designer, had to convert between input and output (or visa-versa) in order to use a cascade analysis tool. Sure, this conversion is simple for most parameters, but converting output P1dB to its input equivalent often led to one particularly perplexing conundrum – do I add “1” or subtract “1” to the gain to determine the input P1dB? “Why, oh why,” you may have cried, “must it be this way?” Well fret no more, because there’s a new cascade analysis tool in town, one that will let you choose between input or output specifications for EACH component in the line up, one that solves the P1dB dilemma for you. That’s right, now you can go straight from data sheet to analysis without hesitation. Let our fancy math equations figure out all the conversions so you can get back to the real questions, such as: “What time is happy hour?” Well, with our calculator, every hour can be a happy one! Onwards, engineers, to microwave system glory!
Cascade Analysis Calculator Cascade Calculator User Manual
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