Performance degradation of some on‐chip finite‐ground coplanar waveguide (FGCPW)‐built passive devices at high temperature

Abstract

At different temperatures, the performance degradation of on-chip finite-ground coplanar waveguides (FGCPWs) and FGCPW-built meander-line inductors are investigated in this article. These passive devices were all fabricated on a double-layer polyimide and GaAs substrates and often used in monolithic microwave integrated circuits. It is shown that the increase in temperature causes the increase in series resistance or conductive loss of the metallization planes, and the temperature coefficient of series resistance depends on both frequency and metallization thickness. At given metal plane thickness and operating frequency, the conductive attenuation constant increases linearly with increasing temperature. Because of the increase in conductive loss, the maximum of Q-factor of each meander-line inductor decreases linearly with increasing temperature. While the temperature effect on the parasitic coupling between two parallel FGCPW stubs or between two neighboring inductors can be neglected, even the temperature reaches 438 K.