of the base plate and of the elements that act as spacers between the passive or active part and the base plate the inventive microstrip structure allows the use of microstrips with different widths in an rf ic without compromising the other important electrical characteristics like impedance level and inductive coupling this opens the door for constructing a balun integrated into an rf ic being able to e g make an impedance matching between different impedance levels application_number US 15493405 A description a microstrip and a ground plane are co operative parts of a transmission line system along which a signal propagates in a form of electromagnetic fields between the microstrip and the ground plane one or more microstrips may use a same ground plane in common in a microstrip structure according to the invention a microstrip is an integral part of the passive or active part of an rf ic and a ground plane is an integral part of the base plate of an rf ic fig4 a 4 b and 4 c present side view cross sections of exemplary embodiments of the invention the part 451 in fig4 a 4 b and 4 c may be either the passive part of an rf ic or the active part of an rf ic and hereinafter the part 451 is referred as u2018 the electrical.