Characteristics of coplanar waveguide on sapphire for high temperature applications (25 to 400° C)

Abstract

This paper presents the characteristics of coplanar waveguide transmission lines fabricated on R-plane sapphire substrates as a function of temperature across the temperature range of 25 to 400˚ C. Effective permittivity and attenuation are measured on a high temperature probe station. Two techniques are used to obtain the transmission line characteristics, a ThruReflect-Line calibration technique that yields the propagation coefficient and resonant stubs. To a first order fit of the data, the effective permittivity and the attenuation increase linearly with temperature.

Temperature Dependency (25 <spl deg>C - 400 <spl deg>C) of a Planar Folded Slot Antenna on Alumina Substrate

“…The attenuation of the CPW lines gradually increases from 0.37 to 0.84 dB/cm as the temperature increase from 25 to 400 C. increases from 5.4 to 6, approximately 10%, over the same temperature range. This is agreeable with [9], [10] when taking into account the metal cladding thickness.…”

High Temperature Characteristics of Coplanar Waveguide on R-Plane Sapphire and Alumina

“…A Thru-Reflect-Line (TRL) [19] [20] calibration is performed at each temperature as described in [17]. To improve accuracy as compared to [17], the measurement procedure is repeated on two similar sets of substrates starting at 25˚ C and increasing the temperature to 400˚ C, and the calculated ε eff and α from each set of data is averaged across the frequency band.…”

“…A CPW open circuit terminated shunt stub with the same S and W as the CPW line under investigation is used as described in [17]. Here, two stubs of length 6455 and 19365 μm are used.…”

“…Sapphire was also characterized by [14]; by dielectric resonators at 60 GHz from -50 to 80˚ C [15]; and by coaxial probes from 0.5 to 3 GHz and 600 to 800˚ C [16]. Recently, the authors presented preliminary characteristics of coplanar waveguide on Sapphire as a function of frequency over the temperature range of 25 to 400˚ C [17].…”

(Invited) High Temperature Wireless Smart Sensor Technology Based on Silicon Carbide Electronics

“…The circuit is composed of a Clapp-type oscillator design and the circuit schematic is shown in Figure 6a. More information on the design methodology can be found in [22]. A Cree CRF24010D SiC MESFET is the active electronic device used in this system.…”