An improved process for Efavirenz, which has several advantages over reported methods like low cost, high yield, better optical purity and industrial feasibility. Additionally, an antenna can be integrated with the surface wave device, wherein the antenna receives one or mores signals, which excite the acoustic wave device to produce multiple modes frequency outputs in which temperature and pressure effect changes are separated from one another for analysis thereof. The elongate member defines a slot which extends along an axis parallel to the central axis. Since the switching losses of the first module can be absorbed outside a cryogenic container, the switching losses do not add to the cryogenic heat load. No mention of cooling and advanced optics to detect the features.