RF Wizard Achieves Significant Time/Cost Savings!

Let's take a typical design example:

Working from a transistor's published Scattering and Noise Parameters, a narrow-band, Common Emitter/Source, Low-Noise amplifier having a maximum Noise Figure of 1.2 dB at a Power Gain of 18 dB (say) is to be designed at some nominated frequency.

Our design tools include a Calculator (perhaps programmable) and some Smith Charts. Generator and Load Impedances and the necessary Scattering, and Noise Parameters are input manually and from these, a number of necessary ReflectionCoefficients are calculated: gamma-G, gamma-L, gamma-IN, and gamma-OUT.

The first complex task is to determine the device's stability via (say) Rollett's Stability Factor and the Determinant of the Scattering Matrix and, if conditionally stable, calculate the centres and radii of the Input and Output Stability Circles. (Note that in order be certain that the design does not cause instability (oscillation) at some other frequency within the transistor's operating range, it would be wise to repeat this exercise for all frequencies).

Next, the centres and radii of a number of Constant Gain Circles are calculated. The number is influenced by the "gain method" employed - in this case, Available Gain or Unilateral Gain are the choices for Low-Noise Design.

Then, the centres and radii of four or more Constant Noise Figure Circles are calculated. So far, around 30+, complex calculations may have been undertaken, each involving Complex Numbers.

The circles (between 12 and 20) are inscribed on a Smith Chart, followed by the selection of appropriate Gammas necessary for the specified design goals.

Finally, input and output matching networks are designed to transform gamma-G and gamma-L to the selected gammas.

Question: How long has this taken?
Answer:    3, 4,...., 8 hours; it depends on how good and/or how practiced you are.

Question: How long would this take using RF Wizard?
Answer:    10 to 20 minutes.


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