Uncertainty analysis of Q-factor measurement in cavity resonator method by electromagnetic simulation
- PDF / 1,751,476 Bytes
- 6 Pages / 595.276 x 790.866 pts Page_size
- 62 Downloads / 242 Views
Uncertainty analysis of Q‑factor measurement in cavity resonator method by electromagnetic simulation Jae‑Hwan Park1 · Jae‑Gwan Park2 Received: 24 January 2020 / Accepted: 23 April 2020 / Published online: 30 April 2020 © Springer Nature Switzerland AG 2020
Abstract Effects of cavity material on the Q-factor measurement of microwave dielectric materials were studied by HFSS simulation and the measurements using metal cavity. TE01δ mode resonant frequency was determined from the electric and magnetic field patterns and the Q-factor was calculated from the 3 dB bandwidth of resonant peak at the scattering matrix S21 spectrum. In the cavity resonator method, Cu metal cavity has been generally used. However, the oxidized surface of Cu cavity could generate errors in Q-factor measurements. From the simulation, it is observed that the Q-factor significantly decreased with decreasing conductivity of cavity metal. When the conductivity of the oxidized Cu is assumed as 1000 Ω−1 m−1, the Q-factor could be decreased by 80% compared to pure Cu. Keywords Microwave · Cavity · Dielectric materials · Q-factor · Simulation
1 Introduction High-Q dielectric materials have been widely studied and used for the microwave passive devices such as resonators and filters. Recently, the miniaturization of microwave components and circuits strongly requires highpermittivity low-loss dielectrics with good temperature stability. Considering the RF frequency range used in microwave telecommunication system (0.3–30 GHz) and the desirable chip sizes in the current packaging technologies (1–10 mm), the dielectric compositions having the permittivity of 20–100 and the Q-factor of hundredsthousands are required [1–3]. Generally, high-Q dielectric materials are based on TiO2 composition such as (Zr, Sn) TiO4, BaO–TiO2–WO3, MgTiO3–CaTiO3, BaTi4O9, and the ZnNb2O6–TiO2 system. In the development of high-Q microwave dielectrics, it is essential to measure the quality factor and the permittivity of the dielectrics. There are several methods of determining the dielectric permittivity and the quality factor of
microwave dielectrics [3, 4]. Among them, transmissionmode cavity resonator method is very useful for the measurement of quality factor of the dielectrics. In this method, disk-type dielectric sample is located in the center of metal cavity and the Q-factor can be calculated from the resonant characteristics of the dielectric disk. However, there could be some error factors in determining Q-factor measurement. Firstly, there could be geometric and/or microstructural imperfections in dielectric resonator. Measured Q-factor could be decreased with the pores and the other phases in the dielectrics [5]. Sintered dielectric bodies have not only a main phase but also some other phases which show different dielectric properties. Also, the imperfections of the metal cavity could also lower the measured Q-factor. In the cavity resonator method, Cu metal cavity has been generally used as it has excellent conductivity and machinability. However, by c
Data Loading...
