A novel analytical model for the UTC-TW photo detector for generation of sub-MM wave signals

Generation of sub-MM waves and THz signals is a difficult challenge, which is being addressed by several research groups. We are using the approach of heterodyning two optical signals in a photo detector. The UTC-TW photo detector has been identified as the device of choice for high frequencies. In this paper we present a novel analytical model, which we have developed as a design tool for the above device. The model was validated for a 60 GHz device, and a new 120 GHz device has been designed. In addition performance limits for the UTC-TW PD are calculated by the new model, and it is shown that this device has the potential of delivering more than 1 mW of power at frequencies approaching 1 THz.