Transmitarray Element Design for Subharmonic Injection-locked RTD Oscillators in THz Band

In this paper, a transmitarray element (TE) is designed for wireless subharmonic injection-locked triple barrier (TB) resonant tunneling diode (RTD) oscillators. It adopts a receiver antenna (RA)-transmitter antenna (TA) structure. The RA is a u-slotted patch antenna, and we use a cubic silicon block at top of this patch, so as to increases the RA gain and radiation efficiency. A fat monopole structure with a slot-like counterpoise is used as the TA. In this design, the RA can receive 100 GHz subharmonic injection signal (SIS). Meanwhile, the TA will radiate the 300 GHz fundamental oscillation signal (FOS) generated by the TB RTD. Moreover, the TA structure can isolate the 300 GHz FOS coming into the RA but couple the received 100 GHz SIS to the TB RTD, which performs like a filter-antenna. In the simulation, the transmission loss in the TA structure is higher than 15 dB around 300 GHz and only about 1.5 dB around 100 GHz. The gain of RA is 6 dBi with 65% radiation efficiency at 100 GHz and the gain of TA is 14 dBi at 300 GHz when applying a 1 mm radius silicon lens at the backside of the InP substrate.