A Plasma Density Measurement Sensor Based on a LTCC Antenna

In this paper, we introduce a plasma electron density measurement sensor based on a Low Temperature Co-fired Ceramics (LTCC) antenna, which has three layers. The variation range of plasma frequency spans from 0.6 to 6GHz, and the resonant frequency of the corresponding LTCC antenna varies from 4 to 5GHz. The measurement accuracy reaches 0.1 GHz, and the measurement accuracy is over 90%. With the increase of plasma density, the resonance frequency of the presented LTCC antenna moves to higher frequencies gradually. The measurement principle is that when the effective permittivity of plasma is different (different densities), the resonant frequencies of antennas is also different. The presented plasma electron density measurement sensor is analyzed theoretically, and numerical analysis are given.