What is the Difference between Lumped Element and Microstrip

Hi,

I just wanna the difference between a stepped impedance low pass filter using a lumped element and microstrip lines ?
and in terms of temperature which one produces more heat at high frequency like 3Ghz.

Thanks

lumped circuits have more parasitic when freq increases above1GHz. so will dissipate more loss i.e. heat

Re: What is the Difference between Lumped Element and Micros

Thanks a lot man
i would love if you could explain more abt that

Distributive circuits have the freedom of tuning their width and length but not discrete.

Discreets at higher freq will not behave the same. per say cap will have added lead inductance etc.

this added inductor is not contributing any benefit and cause to additional loss which is nothing but heat.

hope you understood now.

Thanks for your explanation !

Hello,

A "lumped circuit" approach uses inductors (L), capacitors (C) and resistors (R) to create a function. Parasitics are also modeled with L, C and/or R. You can make a (narrow band) impedance-transforming network with a LC circuit, but also with a microstrip circuit.

A "microstrip" approach uses PCB traces only. The PCB traces are transmission lines. The design procedure is based on transmission line theory and requires a complete other way of thinking. The Smith Chart can be used to design various circuits in a graphical way.

In many cases you see "lumped components" and "microstrip" in one circuit. Both approaches have advantages and disadvantages. Nowadays lumped components can be that small that there is useful behavior far above 1 GHz.

The loss in functions created with microstrip depends on the substrate. FR4 (widely used epoxy/glass laminate) is lossy and heat losses can be significant (depending on the function you require). Ceramic or Teflon (PTFE) substrates have less dielectric loss, hence you can make functions (filters, matching circuits, hybrids, etc) with less loss (then on FR4).