Adjusting method for electrical characteristics of microstrip line filter, duplexer, communication device, and microstrip line type resonator

A method for adjusting the electrical characteristics of microstrip line type resonators, said method comprising:

• (a) providing an aggregate substrate which includes a plurality of microstrip line type resonators, each of said microstrip line type resonators comprising:
• (i) a dielectric having a top surface and a bottom surface;
• (ii) a plurality of resonator electrodes provided on the top surface of said dielectric substrate, and which include at least a first-stage resonator electrode and a last-stage resonator electrode;
• (iii) an input/output electrode which is connected to at least one of said first-stage and last-stage resonator electrodes, and which is provided on the top surface of said dielectric substrate;
• (iv) a first ground electrode which is provided on the bottom surface of said dielectric substrate, and which is disposed so as to be opposed to said plurality of resonator electrodes with said dielectric substrate therebetween;
• and
• (v) at least one second ground electrode which is provided on the top surface of said dielectric substrate, and which is conductively connected to said first ground electrode and not conductively connected to said resonator electrode that is connected to said input/output electrode;
• (b) placing probes of a measuring instrument for measuring the electrical characteristics of said microstrip line type resonators in contact with said input/output electrodes and said second ground electrodes on said aggregate substrate;
• and
• (c) adjusting the electric characteristics of said microstrip line type resonators while measuring the electrical characteristics of said microstrip line type resonators.