This paper presents an original strategy for low-cost generation of Radio-Frequency (RF) phase-modulated test stimuli using a standard digital Automated Test Equipment (ATE). The main idea is to generate a modulated digital signal at relatively low-frequency and exploit one of its harmonic replicas to get a signal at higher frequency. Given the specificity of a digital ATE, which manipulates data in the discrete-time domain, one of the cornerstones of the technique is to identify favorable sampling conditions that preserve the spectral content of the generated signal around the targeted harmonic replica. To this end, a corruption estimator is defined based on an analytical expression of a sampled-and-held digital carrier. The approach is illustrated in this paper using the Binary Phase Shift Keying (BPSK) modulation scheme with the objective of generating a 2.4GHz signal, assuming a maximum ATE sampling rate of 1.6Gbps. Simulation results and hardware measurements are presented, validating the proposed solution.