The Inverter

In the process of designing a lumped element filter, the circuit layout that is usually used to realize the filter is known as the "ladder network". Why ladder? Simply saying, because the layout looks like a ladder. The picture below shows a ladder network that is consisting of only resistors. In a lumped element lowpass …

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Designing Interdigital Filter

There are many distributed line topology that can be used to design a filter. One of these is the Interdigital topology. The interdigital utilizes multiple cascading coupled lines arranged in such a way that the termination of each stub (or called resonator) is alternate between short and open circuit. As one of the planar transmission …

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Transmission Line Filter Using Richard’s Transformation

Transmission Line (TL) In our previous article, we talked about the parasitic capacitance and inductance of circuits designed in lumped element. With majority of device and applications operating in high frequencies, especially with the introduction of 5G at millimeter wave, it is unfeasible to design filters using lumped elements. This is where transmission line type …

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Asymmetric Impedance Scaling and Frequency Transformation

https://youtu.be/acqtEmFCEjs Asymmetric filters are filters whose response are asymmetric in shape. They are useful for many applications that may require a different requirements between the upper and lower stopband. For example difference in upper/lower cut-off frequency, selectivity and insertion loss. This week video, see an example of an asymmetric filter design that applies impedance scaling …

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