choosing proper package size according to the operating frequency in GHz range

Hi,

Could anyone explain how to choose the proper package size for SMD components such as caps, inductors resistors etc. for a particular frequency, please.

Is there a rule-of-thumb or a particular theory for choosing correct component packages at microwave frequencies?

cheers,
per_lube

Get an idea from keyword "low-noise block downconverter" on Wikipedia.
There are images of 11.25Ghz kit that uses 0402 capacitor components .. (zoom the image).
This style of construction can be used well beyond that frequency, but it gets difficult to model.
This is where lumped components get replaced by distributed structures and RFICs bonded on.
There is a lot of overlap - no definite firm line where packages and their size suddenly change.

Lumped inductors get replaced by printed structures, and thin quarter-wave lines at frequencies much above a couple of GHz, often even at UHF.

SMD packages for active devices are used up to about 20GHz. There are exceptions.