Thermally Tuneable Terahertz InSb Patch Microstrip Antenna

A temperature sensing antenna based on the indium antimonide (InSb) semiconductor material is designed and optimized for temperature sensing applications in the Terahertz band. The complex relative permittivity, ε_r, of the InSb-material is studied at different temperatures. A microstrip antenna with InSb patch is designed for temperature sensing with high sensitivity of 1.588 GHz/K. The impedance matching bandwidth is 9.57% with maximum gain of 6.4 dBi at 300 K. Broadside temperature insensitive radiation pattern is obtained. The proposed sensor is designed for temperature sensing range from 250 K to 400 K. The antenna resonant frequency can be controlled via changing the temperature of the surrounding medium with wide tuning range from 264 GHz to 502.2 GHz. The proposed sensor has a wideband frequency tuning range of 90.2 %. The radiation efficiency is increased from 2.5% at T = 250 K to 86.3% at T = 400 K.