Slow wave meander line having sections of alternating impedance relative to a conductive plate

A meander line, comprising:

• an electrically conductive plate;
• a transmission line having a plurality of first and second sections supported with respect to the conductive plate, wherein each first section is located parallel with and relatively closer to the conductive plate than each second section to have a relatively lower characteristic impedance with the conductive plate than each second section, each second section is located parallel with and at a relatively greater distance from the conductive plate than each first section to have a relatively higher characteristic impedance with the conductive plate than each first section, and each second section is further located parallel and adjacent to a separate first section to form a section pair with that adjacent, parallel first section;
• connector means for serially and alternately interconnecting the first and second sections and maintaining an impedance mismatch therebetween and for serially connecting the first and second sections of each section pair;
• and
• switch means for selectably shorting together the sections of each separate section pair, wherein the switch means are located at predetermined positions between the first and second sections of each separate section pair.