This paper presents for the first time the design, electromagnetic modeling and simulation of a W-band micromachined receiver with a double folded slot antenna. The antenna was processed on a thin dielectric membrane obtained through wet micromachining of a 400 µm thick, high-resistivity silicon substrate. A stand-alone antenna structure was fabricated and characterized in terms of reflection losses, showing a working band (defined for |S11|<-10 dB) between 88.3-105.8 GHz, in good agreement with simulations. The maximum simulated directivity at 94 GHz is 6.3 dBi. The direct conversion receiver uses a hybrid integrated GaAs zero bias detector diode. Two new parameters based on the incident isotropic power are introduced: isotropic voltage sensitivity and isotropic tangential signal sensitivity. The measured isotropic tangential sensitivity is lower than-40 dBm between 80-105 GHz, for a 10 kHz video bandwidth.