One-chip integrated resonance circuit with a capacitive pressure sensor

This paper describes the design, realization and measurement results of an integrated resonance circuit, suggested for pressure measurements. The circuit consists of a variable capacitor and a flat coil, i.e. a passive LC resonator. Changes in capacitance are created by pressure changes. The resonance frequency is changed in the resonance circuit. The circuit as a passive resonance circuit is designed for contactless pressure measurement and wireless information transmission in medical and other applications. The circuit was realized as a monolith integrated sensor on silicon. The dimensions are approximately 3 x 3 mm(2). Several variants were realized with different layouts and values. The resonance frequency f(r) and the frequency dependence of the quality factor Q have been measured.