Abstract: Disclosed is a transmitter circuit (14) for use in radio telephone (10), the transmitter circuit including a power amplifier (17D) having an output coupled to an antenna (12) for transmitting an amplified modulated RF signal; a variable gain driver amplifier (17C) having an output coupled to an input of the power amplifier and an input coupled to an output of a modulator (14A), the variable gain driver amplifier being required to output the modulated RF signal within a predetermined dynamic power range having a maximum value; and at least one programmable gain amplifier (PGA1, PGA2) coupled in series between the output of the modulator and the input of the variable gain driver amplifier. The at least one programmable gain amplifier has a dynamic range selected for reducing the dynamic range requirement of the variable gain driver amplifier to be less than the predetermined dynamic power range.

Abstract: Disclosed is a system for the characterization of thin films and interfaces between thin films through measurements of their mechanical and thermal properties. In the system light is absorbed in a thin film or in a structure made up of several thin films, and the change in optical transmission or reflection is measured and analyzed. The change in reflection or transmission is used to give information about the ultrasonic waves that are produced in the structure. The information that is obtained from the use of the measurement methods and apparatus of this invention can include: (a) a determination of the thickness of thin films with a speed and accuracy that is improved compared to earlier methods; (b) a determination of the thermal, elastic, and optical properties of thin films; (c) a determination of the stress in thin films; and (d) a characterization of the properties of interfaces, including the presence of roughness and defects.