Systems and methods for measuring transmitter andor receiver IQ impairments are disclosed, including iterative methods for measuring transmitter IQ impairments using shared local oscillators, iterative methods for measuring transmitter IQ impairments using intentionally-offset local oscillators, and methods for measuring receiver IQ impairments. A support extends from the backside of the shield adjacent a truncated V-groove opening through the upper edge of the shield. By using a database with a simplified storage and retrieval protocol, the data contained therein can be effectively manipulated in real time. Rubbing directions of the first and second alignment films are substantially parallel to each other. The powder reservoir is designed to allow pressurized air to flow around the entire perimeter of either the inner circumferential chamber or outer circumferential plenum chamber.