Here are a number of microwave calculators that have been used, both at microwave and RF. The microstrip line calculator is the self same one used for a well known interdigital capacitor design.
A simple calculator for the characteristic parameters of a TEM mode coaxial line. Non-TEM mode lines are another story.
Simple calculators for the characteristic parameters of a Quasi-Static TEM mode microstrip lines, coupled lines etc... with up to two ground planes and three dielectrics. Add a real substrate from the catalog.
Simple calculators for the characteristic parameters of a perfect microstrip ie; stripline, in various formats. Add a real substrate from the catalog.
Calculators for various type of microwave filter, example: Interdigital, parallel coupled etc.. with a substrate from the catalog.
Design and analysis of multistep parallel couplers, symmetrical, asymmetrical with both the traditional positive cascade and the inverted format.
Design and analysis of various power combiners, multistep wilkinson, triway with filter, power inductors and capacitors for combiners.