“TopoMEMS varicaps” - MEMS comb-drive variable capacitors with tailored stroke-to-capacitance dependence

MEMS variable capacitors with tailored stroke-to-capacitance dependence was designed and tested. The feature of this work is in the design of MEMS capacitors: While changing the value of individual capacitors pair (C
a
and C
b
), a certain value is preserved, such as the sum (C
a
+ C
b
), the sum of the reciprocals (1/C
a
+1/C
b
), and the product (C
a
×C
b
), predefined by the structure. In view of future topological electrical circuits with MEMS components (TopoMEMS) for quantum-inspired calculation circuits, designers are often requested to change individual values while preserving some value. Our tailored variable capacitors (we can call them "TopoMEMS varicaps") can meet such future requests. Pairs of comb-drives capacitance preserving the sum and sum of reciprocals were made by Deep Reactive Ion Etching (DRIE). Its capacitance-to-comb-fingers-stroke dependence was measured, and the results supported our concept.