Polyimide as Antenna Substrate for THz InP-Based Resonant Tunnelling Diode Oscillators

In this paper, a patch antenna fabricated on a thin Polyimide (PI) substrate (ɛ
r
=3.5) is proposed. The antenna can be fabricated for same chip integration with the promising indium phosphide (InP) based resonant tunneling diode (RTD) terahertz (THz) oscillator. The proposed antenna is isolated from the InP by the ground plane which is placed between the InP and PI materials. The proposed structure can solve the antenna performance issues caused by the thick and large dielectric constant InP substrate (ɛ
r
=12.54) when used as antenna substrate. The antenna is designed at 300 GHz. The simulated results show air-side radiation and the effects of the InP on the antenna performance is eliminated.